THE ALGAE 



165 



The auxiliary cell also fuses with the supporting cell of the procarp, and 

 both fuse with the pericentral cell of the vegetative axis, forming a complex 



TRICHOGYNE 



CARPOGONIUM 



BASAL CELL 



PERICENTRAL 

 CELL 



Fig. 155. — Polysiphonia nigrescens. A, Initial of the procarp branch. B, 

 Separation of the carpogonium. C and D, Development of the trichog>ne. 

 E, Fertilization stage. F, Formation of the central cell of the carposporo- 

 phyte. {After Kylin.) 



called the central cell, which apparently only provides nourishment for the 

 developing gonimoblast, since no nuclear fusions occur. 



From the primary cell of the gonimoblast other cells grow out, which in 

 turn bear the carpospores. The latter when liberated germinate to produce 

 asexual plants or sporophytes. Fifty to sixty carpospores may be formed. 



