828 



DR. F. E. BEDDARD ON A 



seem to belong to the same system. These consist of larger but 

 very short stems with finer branches. I have not traced any con- 

 nection between these tubes and the main stems of the excretory 

 system ; but I can, nevertheless, hardly doubt that it exists. 



Text-fig. 115. 



t.v. 



/' I' • , ■ ' 



', M i I 



/ V\l ■ '* i 



// 



n 



/ !i A 



\ 





c/a 





'k 



■■ I 



A more highly mag-iiilied section through excretory vessels and adjacent 

 structures of the asexual form of JJrocystidium gemmiparum. 



d.v. Dorsal vessels surrounded by circular muscle-fibre, m. Layer of transverse 

 muscle-fibres separating the cortex (to the right) from the medulla (to the 

 left), n. One of several tubes forming the excretory network and lying, as is 

 shown, in the cortex as well as in the medulla, t.v. Transverse commissural 

 vessel forking to join the ventral vessel (v.v.), which is also bifurcate to receive 

 the branches. 



These ramifications lie in the cortical layer as well as in the 

 medullary (text-fig. 115, n). In one case I observed a narrow 

 duct leading from a wider space to the exterior — at any rate, most 



