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Show 1904.] ANATOMY OF THE LACERTILIA. 7 number of Lizards, more particularly with Chamceleon, of which I have had the opportunity of dissecting four specimens belonging to the common species, Ch. vulgaris. The other genera, with which I deal in a less comprehensive way, are Pygopus and the Geckos Phelsuma and Tarentola. Of the genus Pygopus we possess, so far as I am aware, no knowledge of the vascular system. Chamceleon has lately formed the subject of some investigations on the part of Prof. Hochstetter, to whose memoir due reference will be made in the course of the following pages. Inasmuch as that anatomist was unable, through a deficiency in injection, to give much account of the hepatic portal system, I am able to add something to the existing knowledge of that aberrant lizard, as well as to confirm a good many of the facts elucidated by Prof. Hochstetter with regard to other tracts of the venous system. C h am e l e o n v u lg a r is . Of this species I have dissected four individuals, of which one was a male and the rest females. The male specimen was fully injected in both venous and arterial systems : one of the female examples was injected from the anterior abdominal vein, and the renal vessels were successfully filled as well as the intestinal portal system. I am therefore able to offer some facts concerning both the arterial and venous systems. The latter has been partly described by Hochstetter *, who has specially studied the renal afferent and efferent veins, with a description of which I shall begin. As that anatomist has pointed out, they differ considerably from those of other Lizards; but I shall have occasion to point out in a subsequent page that Pygopus resembles the Chamseleon in one important particular. I am further able to note those points in which the veins in question show individual variation. With Hochstetter's account I find myself quite in agreement; there are, however, a few details to which he does not refer. The afferent renal vein, which is formed by division of the caudal into the two afferent renals below the kidney, receives a number of oviducal veins of which I give a full account later. It also receives at least one vein from the dorsal parietes before the ischiadic joins it. The anterior abdominal vein arises from the afferent renal just at the line of division between the anterior wider and the posterior narrower region of the kidney. From it immediately a brunch is given off which divides into two, of which the posterior supplies the dorsal parietes. The anterior branch is the one referred to by Hochstetter as joining the posterior vertebral in front of the kidney (A in text-fig. 1, p. 8). It appears to me that this vein may be looked upon as the equivalent of the lateral abdominal vein in other Lacertilia, for instance in Iguana +. If this homology be not accepted, then the vein in question is wanting in Chamceleon. * " Beitrage zur Entwickelungsgeschichte des Venensystems, &c., " Morph. Jalirb. xix. p. 462. f " On the Venous System in certain Lacertilia," P. Z. S. 1901, vol. i. p. 439. |