Mesoearpese 



337 



Subsequently new continuous layers are deposited internally and the wall 

 becomes differentiated much as in the Zygnemea?. The relics of the 

 gametangia containing the disintegrating remains of the unused portions 

 of the original protoplasts remain firmly attached to the spore for a long 

 time. 



Fig. 211. A D, Mougeotia (Gonatonema) tropica W. & G. S. West, showing four stages up to 

 the completion of the aplanospores. E G, Mougeotia (Gonatonema) ventricosa (Wittr. ) 

 Collins. H and I, Mougeotia producta W. & G. S. West. All x 468. 



The peculiar conjugation of Mougeotia has been interpreted in various ways. De Bary 

 ('58) regarded the H-shaped cell formed by the completion of the conjugation-canal as 

 constituting the zygospore, but that it differed from all other zygospores of the Conjugatse 

 in not being contracted. He considered that this zygospore existed for a very short time 

 as such, but that after the fusion of the ' chlorophyllaceous bodies (not the whole of the 



w. A. 22 



