146 



DEVELOPMENT OF THE FKOG 



At the time of hatching, the excretory organs thus consist on 

 each side of (1) a head kidney, which is a convoluted tube 

 lined by a glandular epithelium, and opening into the anterior 

 end of the body cavity by three ciliated openings, the nephro- 



KM 

 KU 



FIG. 36. A tailed frog, near the close of the metamorphosis, 

 dissected from the ventral surface to show the kidneys and repro- 

 ductive organs. X 4. 



A, dorsal aorta; F, fat body; GM. glomerulus; KA, archinephric 

 or segmental duct; KM, Wolffian body; KP, head kidney, dis- 

 appearing; KU, ureter; O, mouth; OR, genital ridge; RV, tip of 

 ventricle; TO, oesophagus, cut short. 



