298 The Development of the Postcaval Vein in Birds 
The following table shows a comparison of the development of the 
stem of the posteava in birds with that described by Lewis in mammals: 
Rabbit. ; Birds. 
2 ; : Sinus venosus. 
VY. hepatica revehens communis... : 
Proximal end of ductus venosus. 
Hepatic sinusoids. 
Hepatic simusoids..\... are ca ; : 
Independent islands in caval mesentery. 
Repo cen ein { Right subcardinal and anastomosis 
eer ha SA eee } between right and left subcardinal. 
Caudal to the bifurcation of the postcava in birds it is difficult to 
draw a comparison between birds and mammals. The so-called com- 
mon iliac vein in birds is an independent formation, the proximal end 
being the original proximal end of the great renal vein; the distal end 
of the common iliac is formed by an elongation of the anastomosis be- 
tween the great renal vein and the postcardinal. The external iliac 
vein in birds is also an independent structure, and the internal iliac is 
the posterior portion of the original postcardinal. 
LITERATURE CITED. 
Hocustetter, I'.—Beitrige zur Entwickelungsgeschichte des Venensystems 
der Amnioten. I. Htthnchen. Morph. Jahrb., B. XIII, 1888, p. 575. 
Entwickelung des Venensystems der Wirbeltiere. Ergeb. d. Anat. 
u. Entwick., B. III, 1893, p. 460. 
— Beitrage zur Entwickelungsgeschichte des Venensystems der Am- 
nioten. II. Reptilien. Morph. Jahrb., B. XIX, 1893, p. 428. 
—— Beitrige zur Entwickelungsgeschichte des Venensystems der Am- 
nioten. III. Sduger. Morph. Jahrb., B. XX, 1893, p. 548. 
—— Beitrage zur Anat. u. Entwick. des Blutgefasssystems der Mono- 
tremen. Jena Denkschrift, B. V, 1896, p. 189. 
—— Zur Entwickelung der Vv. spermaticae. Anat. Hefte, B. VIII, H. IV, 
1897, p. 802. 
Ueber den Einfluss der Entwickelung der bleibenden Nieren auf die 
Lage des Urnierenabschnittes der hinteren cardinalen Venen. Anat. 
Anz., B. ITI, 1888, p. 938. 
Ueber das Gekrose der hinteren Hohlvene. Anat. Anz., B. III, 1888, 
p- 965. 
Lewis, F. T.—Development of the V. cava inferior. Am. Jour. of Anat., 
Vol. 1, No. 3, 1902; p: 229. 
McCuurE, C. F. W.—Variations of the Venous System in Didelphys vir- 
giniana. Anat. Anz., B. XVIII, 1900, p. 441. 
Development of the Postcaval Vein in Didelphys virginiana. Science, 
N. S: Vol: XV, No. 3795 1902; p: 529: 
Minot, C. S.—Veins of the Wolffian Body in the Pig. Proc. of Boston Soe. 
of Nat. Hist., Vol. XXVIII, No. 10, p. 265. 
