Fleshy Tissue Research Articles

Nutritional Value of the Aril of Trichilia cuneata, a Bird-Dispersed Fruit

Fruits of Trichilia cuneata (Meliaceae), a common tree in dtiet fotests of Central America, are eaten by a numbet of birds. The fruits are 10 to 12 mm in diameter, covered by a yellowish-brown, capsular exocarp, and contain three to six seeds distributed among three locules. Each seed is covered by an orangish-red aril that averages 59.7 percent lipid and 15.1 petcent protein, which makes this species one of the most nuttitious known. The fleshy tissue of only 15 of 59 other species for which we found data contained at least 10 petcent ptotein (dry wt.). Only nine species of 57 had fleshy tissue containing more than 40 percent lipid (dry wt.). Between 1971 and 1972, weights of whole ftuits decreased by 36 percent, perhaps in response to a severe drought in the area. The decrease was not equally distributed among component tissues of the ftuit. Exocarp decreased by 36 percent, aril by 4 percent, and seeds by 62 petcent, Howevet, the teduction in weight per seed was not so dramatic, fot two teasons. First, the numbet of seeds pet ftuit decreased by 26 percent. Secondly, many seeds did not develop. Thus, the decrease in weight per normally developed seed was only 18 percent. The fruit of Trichilia cuneata was atttactive to both specialized (4 species) and opportunistic (11 species) ftugivorous bitds and is intermediate (a generalist) in several dispersal-related characteristics.

Indolyl-3-acetic Acid and Ethylene Levels in Ripening Apple Fruits

Indolyl-3-acetic acid (IAA) levels in apple (Malus domestica Borkh.) fruits were determined fluorimetrically after formation of 2-methylindolo-α-pyrone in purified extracts. The properties of the fluorescent products in apple samples were identical with those of authentic IAA. The assays were performed on samples of cortex with or without peel from the varieties James Grieve and Worcester Pearmain during the last 50—70 d of their development on the tree. At the same time the ethylene concentration in the core cavity of the fruits was measured as a guide to the progress of ripening. IAA concentration showed a 3—4-fold increase prior to the rapid rise in ethylene concentration but fell to about its original level as this rise occurred. IAA was also measured in the seeds of James Grieve apples, where it rose to a peak concentration and declined before the peak observed in the fleshy tissue of the fruit. IAA in the seeds increased markedly after 15 d storage of the fruit harvested 136 d after full bloom.

The Role of the Fascia in Muscle Surgery

Mishandling of the fascial tissues during surgery on the extraocular muscles accounts for unsatisfactory alignment of the eye in the primary position; restricted movement of the globe; scarred, injected, heaped conjunctiva; and changes in the normal eyelid level. These hardships may be impossible to overcome by performing secondary surgery. The most serious and frequently recurring abuse of the fascia during muscle surgery is the needless penetration of the Tenon's capsule beyond 10 mm. from the limbus, which results in prolapse of the fat cushion into the spaces that are normally between the movable fascial planes and sclera. The prolapsed fat infiltrates into the sclera and muscle capsules and undergoes fibrofatty proliferation; with time, cicatrization of these scarred tissues pulls the eye to a deviated position, restricting its normal movement. Also, the fat cushion migrates forward under the conjunctiva toward the limbus, causing the unsightly appearance of injected yellowish fleshy tissue near the limbus. A patient's ocular motility can be ruined for life and his appearance deformed because of a surgeon's disrespect for the important role Tenon's capsule plays in the motility of the globe.

Auxin-induced Expansion Growth in Disks of Chicory Root (Cichorium intybus)

Expansion growth in response to auxin in chicory root slices is greater than that reported for any other fleshy tissue. Responsiveness depends on time of harvest and duration of root storage.

How Eucalypt fruits release their seed

Living fruits are completely filled with seeds; and although partial dehiscence is usual in some species as soon as the fruit has matured, no seed is shed until the fruit died and the loculi have widened. The widening is accomplished by three mechanisms, illustrated respectively by E. regnans, E. globulus, and E. calophylla. In .E. regnans there is a thin, woody ovary wall which retracts well into the calyx tube. In E. globulus the loculi are surrounded by thick fleshy tissue which shrinks strongly when dried but remains adnate to the rigid exterior calyx tube. In E. calophylla the valves are also rather fleshy, but not adnate to the calyx tube; they shrink strongly in both longitudinal and centrifugal directions. The above three mechanisms serve not only to widen but also to open the loculi. the case of fruits with strongly protruding valves, opening is aided by the outward bending of the valve tips (e.g. E. viminalis). The bending occurs because the dorsal layer of the valve consists of softer tissue which shrinks more strongly than the ventral layer. The other species examined (E. simmondsii, E. urnigera, E. obliqua, E. delegatensis, E. coccifera, E. ficifolia, E. setosa, E. eximia, E. grandfilia, E. aspera, E. clavigera, E. tesselaris) all depend on one or more of the above mechanisms.

THE NATURE OF THE FLESHY SHOOT OF ALLENROLFEA AND ALLIED GENERA

James, Lois E. (Whittier Coll., Whittier, Calif.), and Donald W. Kyhos. The nature of the fleshy shoot of Allenrolfea and allied genera. Amer. Jour. Bot. 48(2): 101–108. Illus. 1961.—A number of genera of the Chenopodiaceae are characterized by what have been called fleshy internodes which make them appear jointed. The fleshy tissue comprises on the average the outer ⅔ of what superficially appears to be the stem. This fleshy tissue contains a vascular network which is continuous with and similar to the vascular network in what has commonly been called the scalelike leaf. The problem is whether this fleshy vascularized tissue is the result of a downward prolongation of the base of the leaf or whether it is actually the true cortex of the stem. The present authors have found that Allenrolfea is uniquely suited to solving the problem of the so‐called fleshy internodes of these allied genera. The origin and development of the fleshy tissue indicate it to be foliar. This conclusion is further substantiated by the shape of the fleshy tissue, its phyllotactic arrangement, the extent of the palisade tissue and underlying vascular network, the pattern of branching of the leaf traces, and the effect of secondary thickening and suberization.

VASCULARIZATION OF ARTICULATED CHENOPODIACEAE AND THE NATURE OF THEIR FLESHY CORTEX

Fahn, A. (Hebrew U., Jerusalem.), and Tova Arzee. Vascularization of articulated Chenopodiaceae and the nature of their fleshy cortex. Amer. Jour. Bot. 46(5): 330–338. Illus. 1959.—The primary vascular system and venation pattern of the following chenopodiacean species with articulated forms were examined: Arthrocnemum glaucum, Salicornia fruticosa, S. herbacea, Halocnemum strobilaceum, Anabasis articulata, A. haussknechtii, A. setifera, taloxylon persicum, H. salicornicum. On the basis of the primary vascular system, classification into 2 types was possible: (a) Salicornia‐Arthrocnemum type, in which the number of the stelar strands alternates between 6 and 8; and (b) Anabasis type, in which the number alternates between 4, 6 and 8. The latter type is assumed to be derived from the former. Similarly, on the basis of the venation pattern of the cortex and reduced leaves, 2 types were recognized: (a) Salicornia‐Arthrocnemum type, in which the cortical network is connected with the lateral branches of the leaf strands only; and (b) Anabasis type, in which the network is connected with both foliar and stelar strands. The view of the foliar origin of the cortex, as postulated by previous authors, is refuted and the present authors consider the fleshy tissue of the internode to be true cortex.

The Bionomics ofLampronia Rubiella(Bjerkander), The Raspberry Moth, in Scotland

The raspberry moth causes serious damage to cultivated raspberries during certain years, particularly in the Scottish fruit-growing areas where it is a major pest. In the south of England it is less abundant, although in recent years there have been indications that it may become more widespread and plentiful there (Massee, 1939, 1942, 1946).The female moth lays eggs during June and July in the fleshy tissue at the base of the corolla and androecium. The larva, on hatching from the egg, feeds for a short time on the surface tissue of the developing fruitlet, but within a few days it penetrates into the fruit to feed on the fleshy receptacle. During this period it casts its skin once. From the fruit the second instar larva migrates in search of a place in which to hibernate. Hibernacula appear to be situated mostly in the soil close to the roots of the raspberry plants. Prior to hibernation taking place, the larva moults for the second time, so that it passes the winter as a third instar larva.With the approach of spring, at the time when the raspberry buds are bursting, the larva leaves its hibernaculum and crawls up a cane until it finds a suitable bud into which it eats a tunnel through the closely packed leaflets. Sometimes a larva, after having consumed the contents of its first bud, leaves it and attacks a second bud which, by this time, may have developed into a young lateral two to three inches long. The larva, which infests a single bud during its spring life, pupates in that bud, but that which infests more than one bud pupates on tie-wires, leaves, canes, supporting posts or similar places. During its spring life the larva passes through another two instars (the fourth and fifth) before pupating.The full-grown larva prepares for pupation by spinning a white silk cocoon in some suitable place. This takes approximately five days to complete. Within the cocoon the larva pupates and the pupa remains for a period of three weeks.Adult moths appear in June and are abundant during the second half of the month. Egg- laying then commences and a new generation of the species begins.The summer larvae, which hatch during July from eggs laid in the flowers by the female moths, do little damage to the fruit because they are very small and their feeding is largely confined to the receptacle tissue.The most serious damage is perpetrated by the larvae which emerge from hibernation in early spring and bore into the developing buds and laterals. Although their primary buds are killed by the caterpillars these are usually replaced by secondary buds; if these in their turn are largely destroyed by migrating caterpillars the plant’s recovery is prevented because there are no further replacements to overcome the second wave of attack.

Determination of Rubber in Fleshy and Woody Tissue Plants

Determination of Rubber in Fleshy and Woody Tissue Plants

Studies in the Trigonocarpales. Part II. Taxonomic Problems and a Revision of the Genus Pachytesta

Paleozoic seeds are usually found as isolated, detached organs, and the difficulty of determining relationships has long been recognized. In isolated specimens known with structure preserved general relationships to leaf and stem types are generally proposed based on anatomical similarities. Even then such seeds are generally referred to distinct organ genera. A recurrent problem exists when isolated seeds known only from superficial characters or insufficient structural features are assigned to the same genus as those known with structure well preserved. The basis of this difficulty lies in the extreme variability which may be obtained by a single type of seed depending upon the nature and state of its preservation. For instance, in the radiospermic seed Pachytesta vera, the anatomy of which was described in considerable detail in Part I (Hoskins and Cross, 1946), it is possible to find several preservation forms. Some of these are complete seeds but others may have lost varying amounts of outer tissue. They may be altered, flattened, or variously changed in form. If the surface appears essentially smooth, with longitudinal striations occurring irregularlv, it is of the Neuropterocarpus-type shown diagrammatically in figure 49. These striations may be an expression of sclerenchyma strands in the outer tissue, of vascular bundles within the outer fleshy layer, or as shrinkage phenomena. A second type may be either completely or partially decorticated with its surface marked by numerous more or less strongly developed ridges of the Holcospermum-type as shown in figures 49 and 55. These ridges may varv widely in origin. They may be an expression of the surface of a much ribbed, strong, stony layer either showing through a compressed or shrunken layer of outer fleshy tissue, or the actual surface of the stony layer if all external tissues have been lost; or they may represent the vascular system of the nucellus either as casts or molds of the inner or outer surface of the mature nucellus as in figure 55.

Notes on Cryptoporus Volvatus

Crytoporus volvatus is unique among polypores, for the porebearing layer is hidden by a volva. It is thus often termed the hidden-pore fungus or the volvate polypore. During the fall of I9II, the writer frequently found this species on fallen coniferous trunks. Since that time, many specimens of it have been collected. They were growing from such hosts as Douglas fir (Pseudotsuga taxifolia), Ithe western hemlock (Tsuga heterophylla), and white fir (Abies grandis). During the months of March and April, I912, I had the opportunity of observing quite thoroughly the development of the sporophores of this fungus, an,d a few words might be said here to supplement what Peck (3) has already said concerning some advanced stages of the pileus. Two trees of Tsuga heterophylla found on the campus at the University of Washington were thoroughly infected. This gave splendid opportunity to observe the sporophores in different stages. The very young stages of the sporophores of Cryptoporus are globose and covered with a thick crust of reddish-brown resin exuded from the tree. As the button grows, this crust becomes thinner and thus the sporophore appears to grow lighter in color. Because of this coating of resin, no satisfactory method of killing and embedding for histological work was found. However, some free-hand sections were made and examined after staining with eosin. In the earlier stages the button is an undifferentiated mass of fungous filaments. The cortex is soft-fleshy, hygrophanous, and white. Soon a tiny spherical cavity appears in the center of the button, when the latter is from 3 to 4 mm. in diameter. This increases in size with the growth of the button and the fleshy tissue increases in thickness up to about 3 mm. Until the sporophore is about 12-20 mm. in diameter, the tissue is about the same 121