Small Fissures Research Articles

Uncommon Wall Thickenings in the Sieve Cells of Pteris wallichiana

Pteris wallichiana Agardh was collected from Kerala, India, fixed in FAA, and processed for microtomy by conventional methods (Sass, 1958). Sections were stained following Cheadle, Gifford and Esau (1953). In addition, 2 KI and H2S04 was used for cellulose, the PAS reaction for insoluble polysaccharides (Jensen, 1962), and Toluidine blue '0' for cell walls (O'Brien, Feder & McCully, 1964). During our study of phloem structure in Pteris wallichiana we observed uncommon papillose thickenings on the walls of sieve cells, rarely in the rhizome and frequently in the rachis. These sieve cells were randomly distributed and generally belonged to the metaphloem. Sieve cells with this thickening did not appear to be structurally different from other sieve cells. The thickenings project 2.4-10.4 tum from the sieve cell wall into the cell lumen (Figs. 1-2). Phloem parenchyma cells having a common wall with sieve cells rarely show this type of thickening (Fig. 4). The thickening may be on only one side of the common wall or it may be on both sides of the wall of two adjacent sieve cells. Occasionally small fissures, some of which may be artifacts, appear in the papillose thickenings, which cause the thickening to appear to consist of different parts (Figs. 5-8). The thickenings are neither tyloses nor, apparently, a reaction to fungal infection. The thickenings are PAS-positive and give a confirmatory test for cellulose. They stain purple red with toluidine blue 'O', a staining reaction similar to the remaining part of the sieve cell wall. A membraneous lining is sometimes observed over the thickenings (Fig. 3). Similar wall th:ckenings have not been reported in sieve elements of other fern species. Warrington (1970) reported papillose cellulose thickenings of cell walls in the cortical cells of rhizome of Geocaulon lividum (Santalaceae), a dicotyledonous plant, but these thickenings were always in pairs on common cell walls.

Effect of bending and stretching of polyethylene strips on the adsorption of surface‐active substances

AbstractThe adsorption of tritium‐labeled sodium stearate and 35S‐labeled sodium dodecylsulfate from aqueous solution on bent and on stretched polyethylene strips was directly measured. The amount of adsorption increased from 2.5 to 4.5 times on surfaces of various polyethylene samples stretched from 5.2 to 5.3 times the original length. For one sample, adsorption increased 8 and 2.5 times, respectively, on the convex and concave surfaces of a bent strip. Autoradiographs of the strips taken after adsorption revealed the appearance of both homogeneous and heterogeneous adsorption on the stretched surface of the polyethylene. The electron micrographs of the strips showed that many small fissures, about 1–5μ in length, formed on their surfaces after the strips were bent or stretched. Enhanced adsorption of the surface‐active substance along these fissures was suggested. On the basis of these observations, it is proposed that in stretching or bending, fissures increase adsorption of the detergent, and the adsorption in turn promotes further development of fissures. Thus, bending and adsorption mutually promote the growth of fissures which finally result in failure of the polyethylene.

Nature of Electrical Contact between Tarnished Surfaces

The variation of contact resistance with temperature has been measured on clean and tarnished silver contacts between 77° and 420°K. It is shown that the temperature coefficient of resistance provides a direct method of distinguishing film conduction from metallic conduction in contacts, and conversely that a single measurement at room temperature cannot reliably yield this information. Clean contacts have the positive temperature coefficient of resistance of the conductor metal. A film-covered contact on the other hand exhibits either of two distinct types of temperature dependence: one with a large negative temperature coefficient, and one that is metallic. It is suggested that these occur according to whether mechanical contact is made on the film or through a small fissure in it. If the contact is mechanically disturbed, the nature of the conduction fluctuates randomly between these two modes. Further, the temperature coefficient of resistance provides a means for distinguishing between semiconducting and tunneling contacts. The experimental observations on silver sulfide tarnish film suggest that electron tunneling is dominant at cryogenic temperatures, but that at normal temperatures the film is an n-type semiconductor.

Genesis of magma for acid calc-alkaline volcano-plutonic formations

Abstract In the Upper Palaeozoic igneous province of the Georgetown inlier, north Queensland, high-level adamellite plutons, extensive rhyodacite ash flows in large cauldrons, and ring complexes containing both extrusive and intrusive phases are developed with equal importance. The igneous rocks were intruded in a semi-stable block adjacent to the Tasman geosyncline during its late-orogenic to post-orogenic stage of development, and the tectonic setting of the province is typical of most large volcano-plutonic formations. The magma for volcano-plutonic formations appears to have been generated by fractional melting (partial fusion) of basic rocks in the lower crust due to the increase in heat flow from the mantle during the orogenic phase of geosynclinal development. In the tectonically unstable zone near the geosyncline, where temperatures were higher, calc-alkaline trachyandesite, andesite, and basalt magmas formed, but away from the geosyncline, beneath the adjacent semi-stable continental block, the lower crust would be less affected by the orogenic forces. Here, pockets of acid magma formed by fractional melting would coalesce and accumulate to form a widespread magma chamber in the lower crust, doming the crust above. The field evidence in the Georgetown inlier indicates that the acid magma was rhyodacitic and rich in volatiles, and that pockets of magma formed up to 200 miles away from the geosyncline. The relaxation of compressional forces accompanying the waning of the orogenic phase, and the doming effect of the magma generated, placed the semi-stable block in a state of tension. During the post-orogenic phase, major basement faults in the block were reactivated; they extended downwards into the lower crust, and finally tapped the acid magma chamber. Magma rose along the faults and was extruded as viscous flows. This caused a drop in pressure in the magma chamber and allowed volatiles to concentrate near the top of the chamber. The volatile-rich magma was erupted mainly as huge ash flows. The cauldron subsidence areas were initiated by the subsidence of the crust above areas where the magma was depleted most. The cauldrons in the Georgetown inlier range from a few miles to 70 miles long, and contain about 2,000 ft. of ash-flow deposits. Before the gas-rich eruptions, ring complexes were initiated in the major zones of weakness within the semi-stable block, and small high-level magma chambers formed in the upper crust by underground cauldron subsidence. Magma differentiated in these chambers was erupted at the surface through a series of ring fractures now occupied by large ring dykes. As the cauldrons developed the excess of volatiles in the lower crustal magma chamber escaped in eruptions through the peripheral fracture zones containing the ring structures, and this initiated the caldera phase of ring complex development: thus the volatile content of magma in the lower crust was maintained at a level suitable for ash-flow eruptions in the cauldrons. Later, during the underground cauldron subsidence phase, magma from the lower crust was intruded as ring dykes and stocks in the ring complexes. The movement of crustal blocks during ash-flow eruptions in the cauldrons opened additional fractures and allowed more magma to rise into the crust. The adamellite emplaced in the Georgetown inlier has a uniform composition; so it was only slightly, if at all, contaminated with basic rocks in the lower crust. Magma rose along the sub-volcanic conduits until it reached a high level in the crust, where it intruded by underground cauldron (block) subsidence. Once this was accomplished, blocks higher in the crust subsided into the high-level magma chambers and the magma rose rapidly to occupy the space of the foundered blocks with very little assimilation. At various stages volatile-rich magma was erupted as ash flows at the surface. Finally, the still-liquid magma filled the spaces remaining after crustal blocks below the base of the ash-flow deposits had subsided. Here, volatiles were lost through small fissures in the roof and the magma crystallized, generally with an even, medium grain size, under an insulating mantle of ash flows about 2,000 ft. thick.

Perianal cellulitis associated with group A streptococci.

OCCASIONALLY in the practice of pediatrics, a mother will bring in a child with a complaint of painful defecation. This symptom is often accompanied by soiling and anal soreness with secondary constipation. In time anal abrasions or small fissures occur which cause more pain, and a vicious cycle of events has become established. Anal erythema or soreness not associated with diaper rash is seldom mentioned in the pediatric literature. Treatment of these patients by general practitioners, pediatricians, or proctologists has been empirical and symptomatic, usually consisting of local ointments and stool-softening adjuvants. We have been impressed that some of these children show a pronounced erythema of the tissue surrounding the anal orifice (Fig 1), and that palpation in this area with the gloved finger discloses a somewhat boggy consistency and also causes discomfort to the child. Since, in one of these children, a cotton swab rubbed over the lesion and

A Model of Composite Propellant Combustion Including Surface Heterogeneity and Heat Generation

The surface heterogeneity of a composite propellant is incorporated in a model of the propellant combustion process. This process is pictured as the sum of fuel pyrolysis, oxidizer decomposition, heterogeneous chemical reaction between the fuel and decomposed oxidizer in small fissures surrounding individual oxidizer particles, and gas phase combustion of all final decomposition products. Expressions for the burning rate and the rate of heat generation at the propellant surface and in the gas phase flame are formulated, explicitly including the oxidizer particle size distribution. Expressions for the mean, one-dimensional, propellant surface and flame temperatures are derived assuming planar regions of heat generation. A collected set of implicit, algebraic equations is solved numerically for the propellant burning rate, surface (and flame) temperatures for a variety of physical parameters. The burning rate is found to depend strongly on the oxidizer particle ignition delay at low pressures, and upon the position of the external flame at high pressures. The effect of the heterogeneous reaction on the burning rate is strongest at intermediate pressures. The results agree quite well with experimental data on the effect of pressure and oxidizer particle size on composite propellant burning rates, surface temperatures, and surface structure.

EXPERIMENT IN THE APPLICATION OF MICRO-STRUCTURAL ANALYSIS IN STUDIES OF STRUCTURES OF VEIN-TYPE DEPOSITS IN GRANITOIDS

The structural relations of small fissures within veins of the East Kounrad molybdenite deposit, Kazakhstan, are shown through microstructural analysis to be post-intrusive features of the granitoid massif. M. Russell

The opening and shedding mechanism of the female cones of Pinus radiata

The opening of the female cones of P. radiata has been shown to result from differential shrinkage between the adaxial vascular tissue and the abaxial sclerenchyma of the cone scale. The organization of the secondary wall of the tracheids typically consists of three helically organized concentric layers. In the outer and inner layers the microfibrillar orientation is approximately transverse, and in the middle layer the helix makes an angle of c. 40° with the longitudinal cell axis. In the sclerenchyma the secondary wall consists of wide layers in which the microfibrils of the lamellae are almost transverse to the longitudinal cell axis, alternating with narrow layers in which the microfibrils of the lamellae are almost parallel to the cell axis. Opening is preceded by a severance of the vascular connection between the cone and the stem or branch by the occlusion of the lurnina of the tracheids of the peduncle with resin. As radial growth of the stem proceeds, small fissures develop between the xylem of the stem or branch and that of the cone peduncle. The fissures become filled with resin and there is a progressive erosion of the tracheids of the peduncle until ultimately the xylem of the peduncle is separated from that of the stem or branch.

Roentgen visualization fo cerebrospinal fluid fistula with contrast medium.

Cerebrospinal rhinorrhea and otorrhea with or without pneumocephalus (2) are not unusual complications of head injuries. In the majority of cases loss of cerebrospinal fluid subsides spontaneously by closure (9) of the meningeal tear, and air within the meninges is absorbed. In those cases, however, in which the discharge of fluid following trauma does not cease, it is mandatory (6) to close the fistula by operative means, mainly in order to prevent meningitis, but also to stop fluid loss and intracranial hypotension with their inherent dangers. X-ray visualization of the bone defect of the skull which accompanies the fistula usually presents serious technical problems, which cannot always be overcome even with the help of special projections, stereoscopic views, or laminagraphy (7). Special difficulties may be encountered in cases of so-called frontobasal fistulas in the region of the ethmoidal cells. It may be impossible to recognize fractures in their thin bony septa (4), or even to decide clinically on which side the fistula is located, and whether it is solitary. Multiple fistulous openings, especially in the cribriform plate, may occur on both sides (5) of the septum and are not uncommon. The advantages of accurate preoperative localization of bone defects are, therefore, obvious. A number of films may be taken in order to visualize a small fissure, but such an attempt is generally unsuccessful. In addition to the routine views, seven different diagnostic x-ray methods to achieve this purpose are listed by Brandt (3). Nevertheless, the desired result is rarely obtained. To our knowledge, no account has so far been published of the use of a contrast medium to visualize a cerebrospinal fistula. In the case to be reported here such a procedure was performed successfully and made possible precise preoperative localization of a fistula without complicated radiological measures. Case Report J. E., a 24-year-old army officer, sustained a severe head injury on Aug. 11, 1960, by accidental explosion of a hand grenade, causing a comminuted fracture of the frontal bone, mainly on the right (Figs. 1 and 2). The roof of the right orbit was completely destroyed. The right eye was lost. The frontal dura and the right frontal lobe were lacerated, and there was a perforating wound of the left globe. There were superficial injuries of the chest and abdominal wall. First Operation: The edges of the wound in the right frontal region were débrided and a great many small bone fragments were removed. An intracerebral hematoma in the right frontal pole was evacuated, including destroyed brain substance. Repair of the dura was made difficult owing to the loss of tissue covering the floor of the right anterior cranial fossa. With free pericranial graft, however, what appeared to be a satisfactory closure of the dura was accomplished.

Our common task

The history of education has been a series of stormy, volcanic eruptions which have periodically changed the character of American Education. Educators have been hampered because they have been without one consistent aim. Education has been a public enterprise and therefore at the mercy of certain pressure groups, individual opinions, and community whims. Educators have also been hampered because the great philosophers of education have interpreted the values of education individually and personally. Each has been an educational missionary who gathers a group of followers, deviates from other groups, and eventually becomes powerful enough to break through a small fissure in the side of the volcano of education and start another little volcano.

En postkarelsk peridotit i urberget norr om Torneträsk

Abstract A post-Karelian peridotite in the Archacan bed-rock north of Lake Torneträsk, Northern Sweden. The bed-rock north of Lake Torneträsk is very monotonous, consisting only of late-Karelian granite and migmatite. Among those rocks is found, however, at Råvåive on the peninsula of Pieksennenä, an ultra-basic rock, intrusive in the granite. It is a peridotite consisting of slightly serpentinized olivine. The type is the same as is found in many places in the mountains along the border between Sweden and Norway, belonging to the deepest parts of the Caledonian geosyncline. Besides the peridotite are found soap-stones, consisting of almost pure tale. The shape of the small ultra-basic bodies is seen from Fig. 2. They are very irregular, partly because the intrusions have taken place along fairly small fissure zones in the older rock. No other rock of this kind younger than the late-Karelian granite is known from the Swedish Archaean. The only rocks that could be compared with it are the already mentioned peridotites of the Caledonian mountains. Although the Råveåive peridotite is situated 8 kilometers beyond the border of the Cambro-Silurian rocks, it is possibly of Caledonian age. This opinion is supported by the presence of post-Karelidie tectonic in this region. Sharp, fairly flat-lying faults — or steep overthrusts — similar to the Caledonian ones, are seen at some localities not far from Råveåive. As no post-Karelidic movements are known from this part of Sweden apart from the Caledonian ones, the faults and probably the peridotite too are considered to be of Caledonian age, i. e. the peridotite intrusion has taken place during lower Ordovician or somewhat earlier.

Zonal mineralization and silicification in the Horseshoe and Sacramento districts, Colorado

The Horseshoe and Sacramento districts lie near the Alma and Leadville districts, Colorado. Paleozoic sedimentary rocks intruded by Tertiary (?) porphyry sills are folded into a northwestward trending asymmetrical anticline, whose steep west limb is broken by the London reverse fault, with an apparent vertical displacement of around 3,000 feet.All the known ores, which form small silver-lead replacement deposits along small fissures in pre-Pennsylvanian dolomites, occur on the east or hangingwall side of the London fault. These favorable stratigraphic horizons, which lie just below those that contain the valuable gold-quartz veins on the footwall side of the London fault in the nearby London mine, lie far below the surface west of the fault in the Horseshoe and Sacramento districts.Mineralization includes widespread recrystallization of the dolomites, less widespread replacement of dolomite by jasperoid, and deposition of ore accompanied by additional local wall rock alteration. Field and, particularly, microscopic observations dealing with all these processes are discussed.The ores mainly contain pyrite, sphalerite, galena, tennantite, and argentite in a gangue of quartz, barite, carbonate, and recrystallized and silicified country rock; manganiferous ankerite, luzonite, chalcopyrite, and an unidentified sulphide locally occur in small amounts. These minerals exhibit a zonal distribution as to mineral species, textures, and compositional variations. Following the precedent established for the Leadville region, non-baritic ores in the central zone of ore deposition may be classed as mesothermal, baritic ores more distant as cooler mesothermal, and the most distant as telethermal. The productive area is confined to the intermediate and the inner portion of the cooler mesothermal zones.The jasperoids are grouped into three textural types: (1a) anhedral-nodular, (1b) anhedral-granular, and (2) euhedral. Particularly significant is their zonal arrangement, which reveals the finest-grained textures nearest the center of ore deposition.Economic interest pertains not only to discovery of new orebodies within the area of known mineralization but also to the possibilities at depth in favorable horizons west of the London fault. The question of possible southward continuation of the London gold-quartz veins from the Alma district is highly important but no significant data pertaining to it have been obtained.

OBSERVATIONS ON THE PERMEABILITY OF HYGROSCOPIC MATERIALS TO WATER VAPOUR: I. OBSERVATIONS AT RELATIVE HUMIDITIES LESS THAN 75%

It is pointed out that experimental work has shown that for the transpiration of moisture through hygroscopic materials two distinct regions of relative humidity can be distinguished: (i) A region below some value between 70 and 80% where the moisture movement is proportional to the vapour pressure difference, and (ii) a region of high relative humidity where the moisture movement is not directly proportional to the vapour pressure. A theory is advanced that these two regions correspond to the two conditions in which water may be present in a hygroscopic material: (i) the water may be molecularly adsorbed, that is to say, the water is bound by the affinity of the molecules of water for those of the solid on which it is adsorbed; (ii) the water may be held in small fissures in the sub-microscopic structure of the sorbing material by capillary forces. The mechanism by which the moisture will move through the material would be different in the two cases and would result in the distinction between regions of high and of low relative humidity.A short discussion is given of Fick's law showing the form in which it might be expected to apply in the two cases. Measurements are given for fibreboards showing that below 75% relative humidity the resistance of the board to moisture transpiration is proportional to the thickness. The moisture content gradients through fibreboard samples have been determined. The diffusance through a board in which the moisture content gradient is opposed to the vapour pressure gradient shows that the latter is the important factor, and the determination of the moisture content gradient indicates that at these low humidities Fick's law is applicable.

A New Species of Tuberaceae for America

On August 26, 1930, specimens of Hydnotria carnea Corda were found by the writer, half-buried in the mud, in a path beside the Lower Tunkhanna, a trout stream near Fern Ridge in the Pocono Mountains, Pennsylvania. Two small potato-like fruit bodies were collected and preserved in 70 per cent alcohol containing a little glycerine. When examined microscopically they proved to be hypogaeous ascomycetes and were identified by the writer as either Hydnotria Tzlasnei Berk. & Br., or Hydnotria carnea Corda according to the descriptions in Hesse's Die Hypogaeen Deutschlands. The fruit bodies were irregularly globose and the size of hickory nuts (2.7 X 2 cm. and 2.3 X 1.7 cm.). They are nearly smooth on the exterior surface with a few small fissures or depressions. The color is between flesh and a rusty brown. To the unaided eye there is no distinct peridium. Any slight floccosity may have been lost when the mud was removed. Small canals present in the gleba are lined with the hymenium. The asci are generally long stiped and cylindrical although some are clavate. In size they average 220-34 tu (in upper portion). The spores are usually uniseriate but occasionally biseriate near the middle of the ascus which then appears to bulge on one side at that point. The number of spores varies. Usually 8 are present but in some cases fewer than that. They are irregularly globose. The exposure is composed of thick blunt warts and varies in color from yellow to dark brown. The size varies from 31-36 X 34-37 p including the warts. The exospore varies from 2.5 to 7.7 jL in thickness due to these warts. A few asci lie at the base of the others and are perpendicular to them. The paraphyses are colorless, irregularly cylindrical, septate, much longer than the asci and about 6.8 / in diameter. The banks along the Little Tunkhanna are suitable for the

鉄鋼中の含有瓦斯に関する研究

By improving the vacuum fusion method, apparatus, the accuracy of hydrogen analysis is so increased that it is possible to draw a distribution map of hydrogen in a solid ingot section. As a result it is found that hydrogen content is gradually increased from outer to inner part of the ingot, making nearly homocentric equiconcentration lines. The distribution is caused by the hydrogen diffusion in solid steel after solidification. The stress set up by dissolved hydrogen in ingots is calculated using the data obtained. Under certain circumstances the pressure of hydrogen in a small fissure would increase to overcome the strength of steel, though it has a much lower value in actual cases owing to its high diffusion velocity. The author observed the white spots in a steel billet in which practically no hydrogen was present. It is, however, confirmed that hydrogen promotes the developement of the white spots, but not to be the principal cause of it.

DERMATITIS DUE TO TINCTURE OF GREEN SOAP

A physician, aged 33, complained of an eruption which, for about seven months, had involved the fingers of both hands. Examination revealed a vesiculopustular type of eruption, with considerable scaling about the older lesions, and several small fissures on the flexor surface of the fingers of the right hand. The lesions apparently went through a cycle: from small and at times grouped vesicles, accompanied by severe itching, they changed to broken-down, exudative papules, and, after a week or ten days, to dry, scaly and at times fissured areas. A diagnosis of dermatophytosis was made. Examination of the feet disclosed moderate scaling and maceration between the toes, especially between the third and fourth on each foot, and a few scattered vesicles on the soles. Examination of the feet and hands for tinea repeatedly gave negative results. In spite of the negative results of examinations, the usual routine treatment for dermatophytosis was

A New Meteorite from Ballinger Texas

the U.S. National Museum at Washington, D.C. Nothing is known of the time of the fall of this meteorite. Externally the specimen presents an appearance not unlike that of the typical octahedrite-an irregular mass, noticeably thicker at one end, its surface showing considerable oxidation and several small fissures. The total weight was 1,250 grams, or about 21 pounds. Upon cutting the iron proved to be somewhat granular-the granules being of various shapes and sizes (see Fig. i). Etching produced a very attractive face of variously oriented granules, which under slight magnification exhibited abundant and very distinct

EXPERIMENTAL RESEARCHES ON SENSORY LOCALISATIONS IN THE CEREBRAL CORTEX

1. It is possible to investigate the sensory functions of the cerebral cortex by local application of strychnine.2. Consequent upon such local application to a certain area, which forms what may be termed the “active zone”of the cortex, constant and typical symptoms of excitation occur.3. The application of strychnine to parts of the convexity of the cortex outside this zone is not followed by like disturbances.4. The sensory disturbances produced affect both cutaneous and deep sensitivity.5. The disturbances in cutaneous sensitivity manifest themselves by (a) Symptoms of spontaneous excitation, paræsthesiæ. (b) Hyperæsthesia and hyperalgesia. (c) Exaggeration of Munk's “Berührungsreflexe.”6. The disturbances in deep sensitivity manifest themselves in an abnormal hypersensitivity to pinching and pressure of the bones, tendons, and muscles.7. So far as the sensory functions of the skin of the cat are concerned, both sides of the body are represented in the cortex of one hemisphere, but the opposite side most.8. The disturbances of deep sensitivity consequent on the application of the poison to the active zone of one hemisphere alone are always unilateral and on the contralateral side of the body.9. The so‐called “active” zone may be subdivided, according to the parts of the body where sensory disturbances show themselves, as follows:— (a) Head zone: this includes the sensory representation of the neck as well as of the head. (b) Fore‐limb zone: this includes the sensory representation of the trunk as well as of the fore‐limb. (c) Hind‐limb zone. (d) Zone of “crossed symptomatology.” On applying strychnine anywhere in this zone we find disturbances of cutaneous sensitivity provoked in the ipsilateral fore‐limb and in the contralateral hind‐limb.10. The following parts of the cortex are included in the head zone:— (a) The gyrus sigmoideus anterior. (b) The part of the gyrus sigmoideus posterior in front of the small fissure termed by Campbell “the compensatory ansate fissure.” (c) The frontal half of the gyrus suprasylvius anterior. The gyrus sigmoideus anterior forms the focal area of this zone.11. Included in the fore‐limb zone are the following parts:— (a) The gyrus sigmoideus anterior. (b) The part of the gyrus sigmoideus posterior in front of Campbell's “compensatory ansate fissure.” (c) The frontal half of the gyrus suprasylvius anterior. (d) The middle third of the gyrus ectosylvius anterior. The focal area of this fore‐limb zone is represented in the parts mentioned under (a) and (b).12. The hind‐limb zone occupies the frontal half of the gyrus inarginalis. The focal area of this zone lies in its anterior part.13. The following parts form the zone of “crossed symptomatology.” (a) The part of the gyrus sigmoideus posterior behind Campbell's “compensatory ansate fissure.”(b) A small part of the gyrus marginalis immediately behind the sulcus ansatus.(c) The frontal third of the gyrus suprasylvius medius and a sinall portion of the hinder part of the gyrus suprasylvius anterior.(d) The part of the cortex situated on the transition from the gyrus ectosylvius medius to the gyrus ectosylvius anterior. The more frontally in this zone the application of strychnine is made, the more marked are the resulting symptoms.14. The fore‐limb and head zones almost entirely overlap one another (contrary to the view taken by Munk and Rothmann).15. In so far as any sensory zone overlaps the motor area (the position of the latter being decided by methods different from those herein dealt with), there may be said to exist in the cat, and probably also in the dog, a common sensori‐motor cortical zone, as Munk and others have held.16. The sensory disturbances produced are, in almost all the experiments, most marked towards the distal parts of the extremities.17. Except in one instance, none of my thirty‐four experiments have furnished any proof of a segmental distribution of the sensory disturbances caused by strychnine application to the cortex.18. Except in one experiment, no genuine symptoms of motor excitation —such as muscle twitchings, hyper‐reflexia, and exaggeration of tendon and periosteum reflexes—have been observed. This absence of motor symptoms in my experiments, as compared with those of some other observers, may have been due to the fact that in mine the application of strychnine was always slight and the poison was probably confined to the more superficial layers of the cortex.19. The lobus frontalis has no sensory functions in the cat.

IX. A further minute analysis by electric stimulation of the so-called motor region of the cortex cerebri in the monkey (macacus sinicus)

In a former paper published in the ‘Philosophical Transactions‚’ B., vol. 178 (1887), pp. 153-167, a minute account was given by us of the effects produced by electrical stimulation of the so-called motor area in the cerebral cortex for the upper limb. In continuation of this work we have investigated in a similar manner the effects produced by stimulating the rest of the so-called motor region on the convexity of the cortex, with the exception of the lower parts of the ascending frontal and parietal convolutions. The parts examined in the present research comprise the posterior third of the frontal convolutions, the upper third of the ascending frontal convolution, the superior parietal lobule, and the posterior half of the ascending parietal convolution. The movements evoked by stimulating these areas were respectively those of the head and eyes to the opposite side, conjoined movement of both opposite limbs, movements of the lower limb, and movements of the upper limb. In order to avoid discrepancies in the arrangement of the cerebral sulei in different species, and so to obtain exact localisation of the effect produced, the same variety of Monkey was alone used, viz., Macacus sinicus . In all we have performed twentythree experiments, the animal in each case having been narcotised with ether and killed before recovery from the anæsthetic. PART I.—ANATOMY. In the paper above referred to, a description was given of the position in the Monkey of the fissure of Rolando, the præcentral sulcus, and a small fissure above this, called by Professor Schäfer “ x .” The excitable region investigated in the present paper is limited below, where it lies in front of the præcentral sulcus, by the horizontal level* of the lower end of that sulcus, the superior and anterior part being bounded above by the middle line, and in front by a sulcus which Professors Horsley and Schäfer provisionally named “ y ” (see fig. 1). Below, it is partially bounded by a sulcus which we have temporarily called “ w .” This sulcus, “ w .” runs horizon­tally from near the tip of the frontal lobe backwards to within a very short distance of the vertical limb of the præcentral sulcus, thus lying below and approximately parallel to the upper limb of the præcentral sulcus. The homology between this sulcus and corresponding parts of the human brain has not as yet been made out. The middle part of the region investigated in the present research is bounded above by the longitudinal fissure and below by the sulcus “ x .” The remaining part of this region, situated behind the fissure of Rolando, is bounded above by the longitudinal fissure, behind by the intraparietal sulcus, and below by the horizontal level of the lower end of that sulcus. The upper part of the ascending parietal convolution, or as it is also called the superior parietal lobule, is divided by a small sulcus which is usually vertical, and which has been designated “ z ” by Professors Horsley and Schäfer (see fig. 1).

The Carboniferous System in Scotland Characterized by its Brachiopoda

The shells composing this species vary but slightly in shape, being marginally semicircular, concavo-convex, and about one-third wider than long. The hingeline is straight, and either a little shorter, with its cardinal angles rounded, or somewhat longer than the greatest width of the shell, with rectangular or slightly acute and extended terminations. Both valves are provided with narrow sub-parallel areas, the ventral one, which is the largest, being divided by a small fissure, partially covered with a pseudo-deltidium; while in the middle of the ventral one there exists a prominent V-shaped cardinal process. The ventral valve is moderately convex, and flattened towards its auriculate cardinal extremities. The beak, which is small and incurved, does not overlie the hinge-line; while the dorsal valve assumes in different specimens a greater or lesser degree of concavity, and follows the curves of the opposite one. Exteriorly the surface of the ventral valve is covered with numerous small thread-like radiating striæ, which increase in number by occasional bifurcation, or interstriations at various distances from the beak, so that as many as one hundred and twenty ribs may be counted round the margin of certain specimens, while at irregular distances small spines projected from the rounded surface of the striæ. In addition to these, on each side of the beak there exists along the cardinal edge from five to nine slanting tabular spines, which become longer and larger as they approach the extremities of the cardinal edge. The surface of the dorsal valve is striated as in the ventral one; and minute perforations or punctures may be perceived over the entire surface of the shell, and which are the exterior orifices of the canals which traverse the shell, as in Productus.