48 DEVELOPMENT OF THE DOS-FISH. - 



lining abdominal wall on each side multiply and form the ovary. 

 Anterior set of segmental tubes disappear. Middle forms wolffian 

 body, or parovarium, of unknown function. Posterior forms the 

 kidneys with their duct (ureter). Miillerian duct forms oviduct. 

 Kidney is thus formed of a number of tubes collected in groups, 

 forming the glomeruli of kidney. By blood-vessels being much 

 broken up in these glomeruli, the flow of blood is slow, and thus 

 watery contents are extracted. In male,' anterior segmental tubes 

 form vasa efferentia and epididymis; middle set form wolffian 

 body. Posterior — the kidney. The lower portion of wolffian duct 

 remains as the vas deferens. 



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