424 



THE RABBIT. 



tions on the twelfth day are well seen in Fig. 1 50, where the 

 transversely running Wolffian tubules, KM, opening into the 

 longitudinal Wolffian duct, KC, give the whole organ a some- 

 what comb-like appearance. 



By the fourteenth day, the Wolffian body (Fig. 1 66, km) has 

 increased still further in size, especially at its hinder end; and 



Fig. 166. — A transverse section across the hinder part of the body of a Rabbit 

 Embryo of the fourteenth day, the section passing through the hind 

 limbs, x 12. 



A, dorsal aorta. AA, allantoic artery. CH, notochord. 1*0, centrum of vertebra. 

 KC, Wolffian duct. KD, ureter, or metanephric duct. KM, Wolffian body. KT, 

 kidney or metanephros. LP, hind limb. ND, dorsal root of spinal nerve. NE. spinal 

 ganglion. "NN, ventral division of spinal nerve. NS, spinal cord. NV ventral root 

 of spinal nerve. NY, longitudinal sympathetic cord. TA, stalk of allantois. TC, 

 cloacal aperture on cloacal papilla. TI, intestine. VC, posterior cardinal vein. 



it remains of large size until within a short time of birth. It 

 is the excretory organ of the embryo, and its great size and 

 abundant vascular supply indicate that it is of considerable 

 functional importance. 



3. The Kidney and Ureter. 



The adult kidney, or metanephros, develops in the rabbit 

 in much the same manner as in the chick. 



