CRYPTONEMIALES 



225 



are homologous with the carpogonial branches. After fertiHzation 

 the carpogonium sends down a protuberance containing the 

 diploid nucleus and this cuts off two cells when it is near to the 

 nutrient cells of the carpogonial branch. These all fuse together 

 and sporogenous threads, each carrying a diploid nucleus, then 

 grow out towards the auxiliary cells on the other branches. When 



Fig. 148. Dudresnaya. A-D, stages in development of cystocarp, D. purpurifera. 

 E, F, stages in development of cystocarp in D. coccinea after fertilization ( x 486). 

 G, D. coccinea, carpogonial branch ( x 486). H, D. coccinea, antheridia (X510). 

 (A-D, after Oltmanns; E-G, H, after Kylin.) 



these filaments fuse with an auxiliary cell the latter forms a pro- 

 tuberance into which the diploid nucleus passes, and after this has 

 divided once the protuberance containing one of the daughter 

 nuclei is cut off by a wall. The gonimoblast filaments then grow out 

 as a branched mass from this protuberance of the auxiliary cell. 

 Each sporogenous thread sent out from the original fusion cell may 

 unite with more than one auxiliary cell in the course of its wander- 

 ings through the thallus, so that one fertilization may result in the 

 production of a number of carposporophyte generations. 



CSA 



15 



