194 



THE FROG. 



During the metamorphosis, and shortly before the complete 

 disappearance of the tail, the head kidney separates from the 

 segmental duct. For a short time, a portion of the segmental 

 duct still persists in front of the Wolffian body ; but this soon 



wd / \ \ f 



w V a ti vo 



FlG. 87. — Transverse section through the hinder part of the body of a Tailed 

 Frog during the metamorphosis (cf. Fig. 86). On the right side a spinal 

 nerve is shown, on the left side the vertebral column, x 17. 



A, aorta. CH. notochord. F, fat body. IC, centrum of vertebra. IE, neural 

 arch of vertebra. KA, Wolffian duct. KS, nephrostome. KT, Wolffian body. LGr, 

 lung. LS, stomach. LY, subcutaneous lymph space. ML, myotome. NC, spinal 

 cord. ND, dorsal root of spinal nerve. NN, spinal nerve, main trunk. N"V, ventral 

 root of spinal nerve. NY, sympathetic nerve ganglion. OV, ovary. PA, pancreas. 

 SN, spleen. TI. intestine. "VA, anterior abdominal vein. VI, posterior vena cava. 

 VO, hepatic portal vein. VR, renal portal vein. W, liver. WD, bile duct. WG, 

 gall bladder. 



loses its lumen, undergoes degenerative changes, and disappears : 

 the remaining, or posterior part of the segmental duct, which is 

 now connected with the Wolffian body alone, is from this time 

 spoken of as the Wolffian duct or ureter. 



The vesicula seminalis is a glandular body developed in con- 



