Fig. 131 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 ( X486). H, D. coccinea, antheridia ( X510). (A-D, after 

 Oltmanns; E-G, H, after Kylin.) 



genous threads, each carrying a diploid nucleus, then grow out 

 towards the auxiUary cells on the other branches. When these fila- 

 ments, or connecting threads as they may be called, fuse cyto- 

 plasmically with an auxiHary cell, the latter form a protuberance 

 into which the diploid nucleus of the connecting thread passes. 

 When the nucleus has divided once the protuberance containing 

 one of the daughter nuclei is cut off by a wall. In the allied Acro- 

 symphytum {Dudresnaya) purpurifera the gonimoblast initial is cut 

 off from the connecting thread on the side opposite the auxiliary 

 cell. In D. coccinea 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 auxiHary cell in the course of its wanderings 

 through the thallus, so that one fertilization may result in the pro- 

 duction of a number of carposporophyte generations. 



237 



