nephrio Malpighian capsules may he regarded as parts of tlio cool. mi 

 pinched off segmental!}-, much as those of the pronephros wore. The 

 coelom has thus given rise to two series of dorsal diverticula', Mal- 

 pighian capsules, which remain connected with the ventral 

 tubes with funnels, while their openings into the other nephrie tubules 

 are regarded as another primary set of funnels. 



The pronephrie duet serves also for the nicsonophros and the two 

 organs are also connected in another way: each segmental Malpighian 

 capsule of the mesonephros is connected with a longitudinal cord of 



This longitudinal cord, on each side of the hody, runs hack tothecloaeal 

 region and is continuous anteriorly with the series of pronephrie Mal- 

 pighian capsules: in fact as the latter degenerate they become incor- 

 porated with the anterior end of this cord. The cord is thus a sort of 

 degenerated remnant of a longitudinal coelom tube coiinectf d with the 

 pronephrie tubules and by solid cords with the mesonephric Malpig- 



body distin guie il body of each side. 



The Miillerian duct arises dorsal to the nephros and without any 

 connection with the pronephrie duct. 



The free ventral part of the germinal fold becomes the fat body, 

 some of the dorsal part the germinal epithelium. This germinal epi- 

 thelium is ventral to the nephros and connected by a loose meshwork 

 of epithelial cords with those similar cords connecting the primary 

 mesonephric Malpighian capsules with the interrenal body, lhis 

 network disappears in the female hut remain-, in part, in the male as 

 the tubules conveying the sperm to the kidney. The reproductive 

 gland is not segmentally divided nor are the ana.-tom 

 going to the kidney. 



In applying these facts to the understanding of the urino-genital 

 organs of vertebrates past and present the author regards Tehthfopku 

 as presenting many ancestral traits. 



Thus the primitive nrino-genital system of the v'raniata consisted of 

 pronephros and germinal ridges extending from the region of the 

 heart to the cloaca. The germinal cells discharged into the unaegmen- 

 ted dorsal part of the coelom were taken up by the segmental funnels 

 of the pronephros. Later this dorsal coeb.raic space became pinched 

 off, except for the connecting external funnels of the pronephros and 

 by ingrowth of glomeruli was converted into a series of .' 

 capsules. Still the reproductive cells pass into these capsules by tubes 

 that elongate as the capsules become more deeply retro-peritoneal. 



