36 
DR. H. GADOW ON THE CLOACA AND ON THE 
urinaire, Geoffroy ; or, canal uretro-sexuel in Struthio ; eigent- 
liche Kloake, Budge ; loge uro-genital, Retterer. 
PD = proctodseum = bourse de copulation or bourse du prepuce. 
Geoffroy ; Vorhof der Kloake, Budge ; vestibule genito-excre- 
mentitiel, Duvernoy ; poche postanal-\-passage anal, Retterer. 
F = the fold between the urodseum and the proctodseum, shaded 
grey = le veritable col de la vessie, Geoffroy ; = repli uro-anal, 
Retterer. 
rc = the fold between the urodseum and the coprodseum, coloured 
dark-blue= premier bourrelet ou le veritable anus, Geoffroy; = 
repli uro-rectal, Retterer; sphincter rectal, Martin-St.-Ange. 
rc l = the fold which shuts the inner end of the coprodseum, shaded 
with vertical lines. 
sph. = m. sphincter ani, shaded with crossed lines. 
p = the copulatory organ, shaded grey. 
Ur. = ureter. 
Gen. or v. d. = genital duct, 
B. F. = bursa Fabricii = bourse de Fabrice or bourse accessoire, 
Geoffroy. 
AS = anal pouch or anal sac. 
Fig. 17. Lacerta ocellata, 8. —Type A, with a urinary bladder. In figs. 17-19 one of 
the paired copulatory organs only is shown. 
Fig. 18. Monitor, 8 .—Type B, without a urinary bladder. 
Fig. 19. Typical snake, ¥ .— Tropidonotus. 
Fig. 20. Typical bird. 
Fig. 21. Struthio. 
Fig. 22. Crocodile, adult.—Anal glands not figured. 
Fig. 23. Crocodile, very young, or embryonic. 
Fig. 24. Frays. —Penis stretched out. 
Fig. 25. Testudo. —Penis withdrawn. 
Fig. 26. Ornithorhynchus, 8, adult. 
Fig. 27. Ornithorhynchus, 8 .—Transverse section through the middle of the urodseum. 
Fig. 28. Macropus giganteus, 8, adult.—Retr. = m. retractor penis. 
Fig. 29. Anthropoids, ¥. 
Fig. 30. a-f .—Diagrammatic representation of six stages of the phylogenetic 
development of the sinus uro-genitalis, and the gradual formation of a 
ventral chamber or uro-gonodseum. 
The black line indicates the course of the sperraa. 
The blue line indicates the course of the urine. 
a. Crocodil ian stao-e. 
O 
