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Show 1904.] ANATOMY OF THE LACERTILIA. 437 the flow of the injected fluid, which passes freely into the system of the vena cava as well as into the vessels of the various portal systems. In this way I have found it possible to make accurate sketches (as I hope) of the course of the veins in certain Lizards, and to add something to the existing knowledge of the subject. This knowledge is, however, already very considerable, but refers mostly to Lacerta, of the venous (and arterial) systems of which there are many excellent figures*. These sources of information are, however, mainly concerned with the more general aspects of the circulatory system, and many details are absent. Thus Jourdain t, in figuring + the vena cavse and anterior abdominal vein, omits the epigastric veins, and his figure § of the suprarenal portal system takes account of a few vessels only- unless, indeed, Lacerta differs greatly from the type which I myself have examined. This criticism cannot be applied to the most recent and the most important memoir upon the subject known to me-that of Hochstetter ||. This memoir contains, in addition to embryological observations, a number of facts relating to the venous system of the adult Lacerta and some other genera of Lizards, together with a bibliography. I shall refer to the facts detailed by Hochstetter in the course of the following contribution to our existing knowledge of the venous system of the Lacertilia. Iguana tuberculata. Of this species I have dissected three examples, all of them females. The vena caret posterior lies entirely to the left side of the mesorectum, instead of on the right side as in Tiliqua. It arises by two branches, one from behind the middle point of each kidney and quite concealed by the pelvis. At about the middle of the kidney the vein divides into the larger vena cava which runs on the right side and a smaller left branch. Anterior Abdominal vein.-The accompanying drawing (text-fig. 88, p. 438) illustrates the detailed branching of the anterior abdominal system, which is more complicated than that of Tiliqua which I describe later. At its origin from the vena aclvehens anterior the abdominal vein receives several branches from the parietes both right and left. The veins from the two fat-bodies do not only form their respective halves of the abdominal vein. After the junction of the two vessels to form the median unpaired anterior abdominal, three branches from the right and two from the left fat-body join the anterior abdominal. The exact details are shown in the drawing to which I have already referred. Epigastric vein.-The median epigastric vein is constructed * For instance, in Parker & Haswell, ' Text-book of Zoology,' London, 1897. f " Recherches sur la veine porte renale," Ann. Sci. Nat. (4) xii. p. 134. X Loc. cit. pi. xi. fig. 1. § Loc. cit. pi. xi. tig. 2. || " Beitrage z. Kntwicklungsgeschichte des Venensystems der Amnioten, ii. Rep. tilien," Morpli. Jahrb. xix. p. 428. 29* |