476 



COMPARATIVE ANATOMY 



-mi 



The testes of Sauropsida correspond in position with the 

 ovaries, and, like them, increase in size in the breeding-season ; 

 in Birds, one is generally larger than the other. They have an 

 oval, round, or pyriform shape (Figs. 346 and 358), and are made 

 up of greatly convoluted seminal tubules connected by fibrous 



tissue. In Reptiles (e.g. Lacerta, 

 Anguis), " yellow bodies," which 

 correspond to adrenals (p. 495), lie 

 along the outer border of the testis, 

 and at this point transverse canals 

 pass out from the testis to the epidi- 

 dymis. The latter consists of greatly 

 convoluted canals, and from it arises 

 the vas deferens (Wolffian duct), 

 which either takes a straight course, 

 or is more or less coiled. In Birds 

 it opens by an independent aperture 

 into the cloaca, while in Lizards it 

 fuses with the ureter shortly before 

 entering the latter. 



Remains of the Miillerian ducts 

 are present in the male, correspond- 

 ing in position with those of the 

 female. Their lumen is not continu- 

 ous throughout, but the abdominal 

 aperture may remain open (Emys 

 europsea), and exceptionally (c.fj. in- 

 dividuals of Lacerta viridis) they 

 may be as well developed as in the 

 female. 



Accessory genital glands are pre- 

 FIG. 358. MALE URINOGENITAL se nt in most Reptiles, as in Am- 

 (Aiter F Leydi" 5 )"" Jra<Jlhs - phibians, but it is doubtful whether, 



or to what extent, they are compar- 



B, urinary bladder ; Ep, parpr- able to thoge of Mammals (p. 484). 

 cms ; no, testis; m>/, vestige _ T . 1,1 n i i i 



of the Miillerian duct'; X, kid- In Lizards they are well-developed 

 ney ; p, common aperture of on the dorsal and ventral walls 

 the ureter (Ur, V) and yas Q f the cloaca and their sec retion 

 delerens on a papilla on the , , , 



dorsal wall of the cloaca (Cl) ; passes into the grooved penes in the 

 r, rectum ; Vd, vas deferens ; male. In Snakes similar glands 

 t," yellow body" (adrenal). are p resent) and in mature Croco- 

 diles odoriferous (" musk ") glands 



open into the cloaca, and are said to be eversible. Accessory 

 genital glands are wanting in Chelonians : in those in which 

 so-called " anal vesicles " are present, they are hydrostatic in 

 function. 



Lymphoid organs are present in many Reptiles, and probably 

 here also have a physiological relation to the generative organs 



