Lacerta Muralis Research Articles

Influence of photoperiod and temperature on testicular recrudescence and body growth in the lizards, Lacerta sicula and Lacerta muralis

Annual testicular cycles in the lizards Lacerta sicula and L. muralis appear to be regulated by the interaction between seasonal changes in body temperature and an endogenous rhythmicity in thermal responsiveness. Photoperiodism does not appear to be an important factor; i.e. testicular activity does not appear to be regulated by daylength.Following testicular regression in July, the lizards are refractory to sexual stimulation by high temperatures (i.e. normal preferred levels) for about five months. High temperatures accelerate gonadal regression and prevent recrudescence during late summer. Reduced temperatures stimulate testicular enlargement and spermatid formation during the autumn; this recrudescence can be blocked by treatment with testosterone. Very low temperatures suppress gonadal activity during mid‐winter.Maintenance of lizards at constant high temperatures (33°C) starting in July suppresses testicular recrudescence until December. Also, testicular collapse occurs in lizards transferred to high temperatures after recrudescence has started. The gonads are stimulated by exogenous gonadotropins at 33°C during the fall indicating that high temperatures reduce circulating levels of gonadotropins.The refractoriness to high temperatures is “spontaneously” terminated during midwinter (December) under a wide range of photo‐thermal conditions. Low temperatures may accelerate the termination of refractoriness. Thereafter, high temperatures stimulate, and are required for the final development of the testes and accessory sexual structures. Thus, the increase in body temperature following hibernation times the onset of breeding in the spring.Temperature also has a marked influence on appetite and growth, independent of photo‐period. Weight gains are greater at 33° than at 20°C. At 33° there is a tendency for abdominal fat bodies to enlarge but with little hepatic growth; whereas, the reverse occurs at 20°C.

Electron microscopic study of pineal innervation in lacertilians

Summary The innervation of the pineal organ of Lacerta viridis, Lacerta muralis and Tarentola mauritanica was investigated by electron microscopy. Non-myelinated and myelinated nerve fibers, both running in pericapillary spaces, were observed. The non-myelinated fibers course mostly in bundles lined by a basement lamina. The fibers are embedded in the cytoplasm of lemmocytes. Their terminals show three types of vesicles: (1) agranular vesicles varying in diameter between 300 and 700A, (2) granular vesicles of the same size, and (3) granular vesicles measuring 800–1670Ain diameter. Although the numerical distribution of these vesicles is variable, the number of the large type granular vesicles is constantly less than the numbers of agranular and small granular vesicles. Synaptic connections between nerve endings and basal processes of pineal epithelial cells were not observed. The morphological characteristics of the non-myelinated nerve fibers and their terminals are strikingly similar to those of the orthosympathetic postganglionic axons innervating the mammalian pineal organ. The myelinated fibers which do not contain granular vesicles run either singly or in small groups. Their number is much smaller than that of the non-myelinated autonomic fibers. With every single myelinated fiber many lemmocytes are associated which did not produce the myelin sheath. These fibers are considered to be sensory pineal fibers, earlier described, which originate from the rare intraepitheial nerve cell bodies and constitute the sensory pineal nerve. In comparison with the pineal photoreceptor cells in most Anamniota, those in the lacertilian pineal have lost some of their typical photosensory cytological characteristics. On the other hand, they contain secretory granules varying in size but being generally larger than the largest granular vesicles in the terminals of the autonomic nerve fibers. Therefore, these elements have been termed secretory rudimentary photoreceptor cells. Earlier findings suggest that an indoleamine, probably serotonin, is stored in the secretory granules. The sensory function of the lacertilian pineal organ is regressive whereas its secretory function is of much more importance. Probably, the autonomic afferent pineal innervation in lizards, now for the first time ultramicroscopically demonstrated, is involved in the regulation of the synthesis, secretion and release of chemical compounds at the level of the secretory rudimentary photoreceptor cells which can be considered the phylogenetic forerunners of the mammalian pinealocytes.

The pineal vascular system in Lacerta muralis, with notes on the venous system of other lizards

Information on the pineal blood system of lizards is very limited. In view of a number of recent suggestions that the pineal complex may function in the secretion and/or storage of hormonal material it was considered necessary to obtain further information on the vascular pathways associated with it. A description is provided here of the pineal circulation in Lacerta muralis. This circulation is extensive and provides both an efficient supply to, and drainage from, all parts of the pineal complex. In particular there is an extensive capillary system draining the habenular, posterior, and subcommissural regions. The differences observed between the pineal venous systems of Lacerta muralis, Lacerta viridis, Chalcides tridactylus, Agama cyanogaster, and Varanus niloticus are also recorded. Such differences are restricted to the drainage systems associated with the dorsal sac and anterior wall of the epiphysis. It is concluded that the abundant pineal vascular system would provide a suitable pathway for removing secretory material from the pineal complex.

The sensory innervation of the pineal organ in the lizard, Lacerta viridis, with remarks on its position in the trend of pineal phylogenetic structural and functional evolution.

The sensory innervation of the pineal organ of adult Lacerta viridis has been investigated. Some specimens of Lacerta muralis lillfordi were also used. In the pineal epithelium, a small number of nerve cell pericarya of a sensory type are present. They lie either solitary or in small clusters close to the basement membrane. The axons originating from the nerve cell bodies, i. e. the pineal sensory nerve fibers, first course in the intraepithelial nerve fiber layer which is only locally present and contains a restricted number of unmyelinated fibers. In Lacerta viridis, the pineal fibers generally leave the epithelium at the proximal part of the organ proper. They then form small bundles which run along the outer surface of the basement membrane in the leptomeningeal connective tissue covering. At the proximal end of the pineal stalk the single bundles assemble constituting the pineal nerve. In Lacerta muralis the fibers leave the pineal epithelium at the proximal end of the stalk running farther down within the epithelium. Many fibers become myelinated after leaving the pineal epithelium. The pineal nerve runs ventralward in the midplane just caudal to the habenular commissure to which no fibers are given off. Continuing their ventralward course between the habenular commissure and the rostral end of the posterior commissure which is traversed by some of them, the pineal fibers reach the dorsal border of the subcommissural organ. Small separate aberrant pineal bundles traverse the posterior commissure at various more caudal levels. Having reached the dorsal border of the subcommissural organ, part of the pineal fibers continue their ventralward course directly running along the lateral sides of this organ to reach the periventricular nerve fiber layer lateral and ventral to it. A restricted number of fibers first turns in a caudal direction running between the base of the posterior commissure and the base of the subcommissural organ before turning ventralward to reach the periventricular layer. Most probably, pineal fibers do neither join the posterior commissural system nor innervate the subcommissural organ. Once having reached the periventricular layer, some pineal fibers curve in a rostral direction while others, before doing so, send a collateral in a caudal direction. Both, the main fibers and the collaterals, contribute to the formation of the periventricular layer. The sites of termination of the pineal fibers could not be ascertained.

In vitro culture of cells from liver of wall lizard, Lacerta muralis

In vitro culture of cells from liver of wall lizard, Lacerta muralis

Vergleichende Untersuchungen �ber die Feinstruktur der Bipolarzellschicht der Vertebratenretina

1. The ultrastructure of the retinal cells of the inner granular layer has been studied in diurnal animals (species: Carassius auratus auratus, Siredon mexicanum, Lacerta muralis, Gallus domesticus, Passer domesticus, Rhesus). 2. Three different types of neurons can be discriminated which correspond to horizontal, bipolar and amacrin cells seen in light microscopy. 3. The classification of the horizontal and amacrin cells as neurons is based on their synaptic contacts with receptors and other cells. 4. The demonstration of synaptic contacts appears to be the only reliable criterion of a neuron concerning cells situated in the inner granular layer, for obvious Nissl substance (granulated ER) is not detectable in most of these cells.

The fine structure of the radial fibres in the reptile retina

The radial fibre system in the reptilian retina is particularly profuse and shows a number of unusual morphological features which may throw some light on its function. Retinas from Hemidactylus turcicus, Phelsuma inunguis, Hemidactylus flaviviridius, Gecko gecko , and Lacerta muralis were examined, using osmium-fixed and aralditeembedded tissue. It is suggested that the complex specialization of structure in the vicinity of the visual cell surface has developed to facilitate interchange of fluids or metabolites across the visual cell membrane in the absence of any intraretinal vessels. It is also suggested that the complex interlocking of the radial fibre processes, particularly in the nerve fibre layer, is probably a means of preserving precise inter-relationships of neuronal material to minimize relative movement in the interests of visual acuity. It is speculated that the profuse glial specialization found on the vitread surface of the cone pedicle may represent one of the pathways for lateral inhibitory impulses passing between adjacent visual cells, particularly since no evidence of synaptic components was found in the cytoplasm of the so-called horizontal cells which are usually accepted to be the structural pathway for the lateral passage of information in the retina. A morphological discrepancy between the light and the electron microscopic appearances of the radial fibre system is discussed, and an explanation offered. Finally, a new retinal layer is described.

La secrezione dell'epididimo e del rette sessuale nei Rettili Studio comparativo

Summary Former researches on proteic secretion of epididymis of Lacerta sicula campestris have been estended to other reptilians, wiz Emys orbicularis, Tarentola mauritanica, Lacerta muralis bruggemanni, Lacerto viridis, Chalcides ocellatus, Chalcides chalcides and Vipera aspis. The unusual property of the granules of Lacerta sicula, which stain with pironine after a treatment by ribonucleasis and other enzymes, has been observed in two more species, Lacert muralis and viridis: in the other Reptilian so far studied the proteic secretions of epididymis, frequently associated with polisaccarides, never show this property.

Endolimax clevelandi, n. sp., from Turtles

Although representatives of the genus have been reported for a considerable number of vertebrate and invertebrate hosts (Wenrich, 1935), there are few records of such representatives in reptiles. The amoeba from the European lizard, Lacerta agilis, first noted by Hartmann and Prowazek (1907) (named Amoeba lacertae by Hartmann in a footnote) and studied more fully by Nigler (1909), and also the one from Lacerta muralis (captured near Naples) studied by Dobell (1914), obviously do not belong in the genus Endolimax. Their nuclear division stages are different and their mature uninucleate cysts resemble those of certain small free-living amoebae. Hartmann (1914) referred to Dobell's species as Amoeba (Vahlkampfia) dobelli. The Endolimax reynoldsi described by McFall (1926) from the American swift, Sceloporus undulatus, with its mature uninucleate cyst, resembles much more the species described by Ndigler and Dobell than it does Endolimax, and therefore probably does not belong to this genus. Sanders and Cleveland (1930), in their paper on Entamoeba terrapinae, mention finding a small amoeba similar to nana (p. 271) in Chrysemys picta. Apparently no cysts were seen. This is the only reference to an Endolimax-like amoeba in turtles that we have found. The form seen by these authors is probably the same as that described below.

The Diencephalon and Midbrain of the American Rattlesnake (Crotalus adamanteus)

Summary (1. ) The nuclear topography of the thalamus of Crotalus adamanteus is similar to that of tiphenodon punctatum and Lacerta vivipara, resembling these forms more than that of the Hydrosauria. (2. ) The lateral geniculate nucleus consists of a dorsal and a ventral division. (3. ) The hypothalamus resembles, in its nuclear topography, that of Varanus salvator and Chameleon vulgaris. (4. ) A nucleus lentiformis, nucleus pretectalis and nucleus geniculatum pretectale have been observed, which are similar to the corresponding cell masses in Varanus and Lacerta muralis. (5. ) The nucleus interstitialis of the medial longitudinal bundle is similar to that of other reptiles. A nucleus interstitialis tegtnentalis commissurae posterioris, such as noted by Curwen and Miller (1939) in the turtle, has been identified in Crotalus adamanteus. (6. ) The lateral and medial forebrain bundles are quite similar to those of Varanus salvator and Lacerta vivipara. (7. ) The optic tracts are similar to those of other reptiles. (8. ) Dorsal and ventral supraoptic decussations have been noted, similar to those found in Sphenodon punctatum by Cairney. (9. ) A well-defined habenulo-thalamic and a habenulo-tectal tract have been noted. (10. ) A dorsal and ventral tecto-thalamic tract, such as noted in other reptiles by De Lange, Cairney, Frederikse and others, have been observed. (11. ) A tractus supraoptico-hypophyseos, similar to the tractus praethalamo-hypophyseos, which Shanklin noted in Chameleon vulgaris, has been noted in Crotalus adamanteus. (12. ) A well-defined octavo-hypothalamic tract was found. (13. ) A complex hypothalamo-pedunculo-tegmental fibre system is present, and a fairly large dorsal hypothalamo-tegmental fibre system has likewise been identified in Crotalus adamanteus. (14. ) Dorsal and ventral tecto-bulbar fibre systems have been noted, which are quite similar to those of other reptiles.

The Theory of Evolution since Darwin

THE most recent development of the doctrine of -I evolution is the revival of Lamarckism-that is, the belief in the inheritable nature of the effects of use and disuse. Just as Bateson in 1894 enunciated the doctrine of the origin of species by sports long before this view was consecrated by the experimental labours of De Vries and given the name of the “mutation theory,” so Eimer (1887) and Cope (1888) rebelled against the Weismannian conception of an unalterable germ plasm totally independent of the effects of the experiences of the body. Eimer put forward the doctrine of orthogenesis. This theory states that variations are the results of the effects of the environment on the complex constitution of the living organism, but that this constitution determines the character of these variations; they are not indefinite, but take place in a few definite directions. Eimer, who chose for his special subject of observation the wall-lizard Lacerta muralis, and later the swallow-tailed butterflies, pointed out that new variations make their first appearance in the later stages of growth and become inherited earlier in life as the generations succeed one another. A beautiful example, he explains, is afforded by the Ammonites, in which new features are first distinguishable in the outer coil of the shell, which is, of course, the youngest and latest to appear, whereas in succeeding strata the new feature is found affecting the more central coils. Thus it will be observed that Eimer draws the most decisive support for his theory from palaeontology. Eimer seems to suppose that he is an opponent of Lamarck, but the only difference between them that I can discover is that Eimer seems to regard external conditions as altering the hereditary tendencies by direct action as sulphuric acid acts on metal, whereas Lamarck considers that external conditions stimulate an \ organism to make a response, and that it is this tendency to response that is inherited.

I. On the Lizards allied to Lacerta muralis, with an Account of Lacerta agilis and L. parva.

The Transactions of the Zoological Society of LondonVolume 21, Issue 1 p. 1-104 I. On the Lizards allied to Lacerta muralis, with an Account of Lacerta agilis and L. parva. G. A. Boulenger F.R.S., F.Z.S., G. A. Boulenger F.R.S., F.Z.S.Search for more papers by this author G. A. Boulenger F.R.S., F.Z.S., G. A. Boulenger F.R.S., F.Z.S.Search for more papers by this author First published: January 1916 https://doi.org/10.1111/j.1096-3642.1916.tb00480.xCitations: 2 *Published by permission of the Trustees of the British Museum. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume21, Issue1January 1916Pages 1-104 RelatedInformation

III. Second Contribution to our Knowledge of the Varieties of the Wall‐Lizard (Lacerta muralis)

III. Second Contribution to our Knowledge of the Varieties of the Wall‐Lizard (Lacerta muralis)

A Contribution to our Knowledge of the Varieties of the Wall‐Lizard, Lacerta muralis, in Western Europe and North Africa.

The Transactions of the Zoological Society of LondonVolume 17, Issue 4 p. 351-436 A Contribution to our Knowledge of the Varieties of the Wall-Lizard, Lacerta muralis, in Western Europe and North Africa. G. A. Boulenger F.R.S., V.P.Z.S., G. A. Boulenger F.R.S., V.P.Z.S.Search for more papers by this authorP. CHALMERS MITCHELL, P. CHALMERS MITCHELL Secretary.Search for more papers by this author G. A. Boulenger F.R.S., V.P.Z.S., G. A. Boulenger F.R.S., V.P.Z.S.Search for more papers by this authorP. CHALMERS MITCHELL, P. CHALMERS MITCHELL Secretary.Search for more papers by this author First published: October 1905 https://doi.org/10.1111/j.1096-3642.1905.tb00035.xCitations: 5Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume17, Issue4October 1905Pages 351-436 RelatedInformation

Note on the Early Development of Lacerta Muralis

ABSTRACT The following paper contains an account of some observations on the early stages in the development of Lacerta muralis, begun during the summer of this year at the zoological station at Naples and completed in the morphological laboratory at Cambridge. It relates chiefly to the mode of formation of the germinal layers and to the early development of the kidney.

The Existence of a Voice in Lizards

THE letters on the existence of a voice in lizards, by M. Pascoe and S. P. Oliver, in NATURE, vol. xxv. pp. 32, 174, gave me much pleasure, being a confirmation of observations first made and published by myself in 1874, but doubted in different quarters. In my paper, “Zoologische Studien auf Capri, II. Lacerta muralis coerulea, ein Beitrag zur Darwinschen Lehre, Leipzig, Engelmann, 1874” (p. 20), I have laid down the result of my observations, in the first instance, concerning the habits of the bluish-black wall-lizard, Lacerta muralis cærulea, discovered by me on the Faraglione rock near Capri, and subsequently on those of other wall-lizards. There, I say: “To the harmlessness (or fearlessness, mentioned previously) of the blue inhabitant of rocks—Lacerta muralis cærulea—I owe the discovery of the animal's intonating capacity, a peculiarity generally ascribed among reptiles to the geckoes and chamæleons, but never observed in wall-lizards till now.”

Colour-Variation in Lizards.—Corsican Herpetology

IN a communication sent to you by my friend Mr. Wallace, under the title, “Remarkable Local Colour-variation in Lizards,” published in NATURE, vol. xix. p. 4, mention is made of the well-known case of Lacerta (Podarcis) muralis, var. faraglionensis, only found on the Outer Faraglione of Capri, but there are many similar cases to my knowledge, and I add a note of them, for the fact, although unexplained, is one of great interest. During the last two years, while engaged in forming a complete series of the Italian vertebrate animals, I have visited and explored most of the Mediterranean islands included in the Italian sub-region, and I have invariably found that our common lizard (Podarcis muralis) constantly presents dark varieties on islets adjoining small islands: this is the case on the Scuola, near Pianosa, on the Scoglio di Mezzogiorno, off Palmarola (Ponza), on S. Stefano, off Ventotene, on the Toro, off Vacca (Sardinia), on Lisca nera, Lisca bianca, and Bottaro, off Panaria (Lipari), on Filfla, off Malta, and on Linosa, near Lampedusa. The extreme cases are those of the Faraglione off Capri and Filfla, where a nearly intense black is obtained; next comes Toro, and next Linosa; only the latter case might be explained by the “struggle for existence” theory, for the lava rocks of Linosa are black; but such is certainly not the case with the other islets, and, pace Dr. Eimer, the Faraglione is gray, while Filfla—on which I spent a pleasant day in October last—is painfully white in the glaring Maltese sun, so that its black lizards are most conspicuous. I may add that few creatures I know vary more in colour than Podarcis muralis, even in the same locality; two most distinct varieties occur promiscuously on the small flat islet Formica di Grosseto.

Local Colour-Variation in Lizards

THIS subject has recently been very fully discussed by my friend, Dr. Max Braun, assistant in the zoological laboratory of the University of Wurzburg. His paper, which has especial reference to the lizards of Minorca and of some of the smaller islets of the Balearic group which lie round that island, is entitled “Lacerta Lilfordi und Lacerta muralis”, and will be found in Part I. of the fourth volume of Prof. Semper's “Arbeiten aus dem zoologisch-zootomischen Institut in Wurzburg” published in May, 1877.

Lacerta muralis cærulea: a contribution to the Darwinian theory

(1875). Lacerta muralis caerulea: a contribution to the Darwinian theory. Annals and Magazine of Natural History: Vol. 16, No. 93, pp. 234-235.