Frederic T. Lewis 239 



surface and the subcardinai ventrally. The suprarenal bod}' extends far 

 beyond the traceable branches of the subcardinai vein. In a 29 mm. rab- 

 bit the relations were similar. The very small and short subcardinai vein 

 ■came from the suprarenal body, from which possibly the cardinal also 

 received some small branches. They could not definitely be followed. 

 In Hochstetter's description the left subcardinai is named the left su- 

 prarenal vein from the first. It is quite probable that the subcardinai 

 may become the adult suprarenal, though I shall not consider it an es- 

 tablished fact until still older embryos have been examined. KoU- 

 mann (98, p. 1:77) writes that it becomes " bis auf unbedeutende Gefasse 

 rudimentar." 



The posterior section of the left cardinal vein becomes divided either 

 above the Urnierenvene, or below it, or below the transverse lumbar 

 vein. Hochstetter (93, pp. 585-586), gives figures of the three resulting 

 •conditions in the adult. In the 21 mm. rabbit the division had occurred 

 below the transverse lumbar vein, as is usual; the 29 mm. specimen 

 had divided above that vein. The Urnierenvene becomes the spermatic 

 vein of the adult; and the remaining part of the posterior section of 

 the left cardinal, into which jt flows, is called the ascending lumbar 

 vein. This lumbar vein terminates in the renal vein, the old anasto- 

 mosis extending from the cardinal through the subcardinai to the op- 

 posite side. N"o later changes of importance occur in these veins. 



The present inaccurate text-book accounts of the development of. the 

 vena cava inferior have justified the reiteration of many well estab- 

 lished observations. Schafer, in Quain's Anatomy, illustrates a very 

 brief description by diagrams from Kolliker. These figures, published 

 in Kolliker's Grundriss in 1884 (p. -104, Fig. 276) among other errors 

 represent the cava as a vessel separate from the cardinals to the com- 

 mon iliacs. Schnltze in 1897 (p. 406, Fig. 357) replaced these diagrams 

 by a modification of those of Hertwig, whose faulty figures have enjoyed 

 great popularity. (See Hertwig, 00, p. 350, Fig. 315.) Kollmann (98, p. 

 470. Fig. 292 A) gives the only accurate diagram of the early vena cava 

 inferior which I have seen. His figure agrees with the description by 

 Hochstetter of the vein on the left side, symmetrical with the vena cava 

 on the right, but Kollmann is misled in stating that the vena cava 

 " sctzi sicli in Terbindung " with the cardinal veins. In this he follows 

 Hochstetter's earlier description (93, p. 569). 



" The posterior vena cava passes over from the liver into the caudal 

 continuation of the caval mesentery (into which small branches from 

 the hepatic venous network also enter), and thence may be followed, 

 in the youngest stage in which I saw the cava, a short distance further 



