120 



ASCOMYCETES AND RHODOPHYCE^. 



Batrachospermum, are the descendants of the fusion nucleus, result- 

 ing from the union of male and female nuclei in the carpogonium. 

 The nuclei of the auxiliary cells never take a morphological part in 

 the formation of the carpospores. According to this view, therefore, 

 the auxiliary cells are merely brood cells, their fusion with the cells 

 of the sporogenous filaments representing a peculiar condition of nutri- 



D 



E 



FIG. 47. Carpogonium and its development subsequent to fecundation in Dudresnya. 

 purpurifera. (After Oltmanns.) 



A, carpogonial branch with young carpogone at upper end. 



B, later stage ; nucleus of carpogonium lies some distance up in trichogyne, whose end is twisted. 



C, still later stage ; nucleus lies in coiled part of trichogyne. 



D, carpogonial branch after fecundation; fusion of sporogenous filaments .s/"with auxiliary cells ; 



az, auxiliary cells. 



E, later stage; sz, sporogenous cells ; az, auxiliary cells. 



tion. A further discussion of this phenomenon is reserved for a later 

 paragraph. 



In order to comprehend fully the statements of the preceding para- 

 graphs, it will be necessary to follow somewhat in detail the process 

 involved in one of the forms referred to, as, for example, Dudresnya. 



In Dudresnya purpurif era, according to Oltmanns ('98), the car- 



