1904.] AXATOMY 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 ai'terial) 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 cav£e 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 know- 

 ledge of the venous system of the Lacertilia, 



Iguana tuberculata. 



Of this species I have dissected three examples, all of them 

 females. 



The vena cava posterior lies entirely to the left side of the 

 mesorectum, instead of on the right side as in Tiliqaa. It arises 

 by two branches, one from behind the middle point of each kidnev 

 and quite concealed by the pelvis. At about the middle of the 

 kidney the vein divides into the largei' vena cava which runs on 

 the right side and a smaller left branch. 



Anterior Abdominal vein. — The accompanying drawing (text- 

 fig. 88, p. 4.38) illustrates the detailed branching of the anterior 

 abdominal system, which is more complicated than that of Tiliqiuc 

 which I describe later. At its origin from the vena advehens 

 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. 

 Upigastric vein. — The median epigastric vein is constructed 



* For instance, in Parker & Haswell, 'Text-book of Zoology,' London, 1897. 

 t " Recherches sur la veine porte renale," Ann. Sci. Nat. (4) xii. p. 134 

 X Log. cit. pi. xi. fig. 1. § Loo. cit. pi. xi. fig. 2. 



II " IJeitriige z. Entvvicklungsgeschiclite des Veneu.systcras der Amnioten, ii. Rerj. 

 tilien," MorpU. Jahrb. xix. p. 428. 



29* 



