212 SEXUAL REPRODUCTION OF RED ALGAE 



duction outlined above is complicated in the majority of the 

 red algae, owing to the fusion of the germinating gametospore 

 with adjacent cells that contain storage foods and from certain 

 of these storage cells the characteristic spore producing branches 

 are developed. In this way, the formation of a larger number 

 of spores is made possible by a single fecundation. Frequently 



Fig. 126. Sexual reproduction in Nemalion: A, tip of branch bearing 

 female gametangium, c, and cluster of male gametangia, an, from some of 

 which the motionless male gametes are escaping. B, first division of the 

 germinating gametospore, g. C, later stage showing the early formation 

 of the branches from which the spores will be developed. D, spores forming 

 at the ends of the numerous »branches. 



a sac-like structure, the cystocarp, is developed about the spores 

 owing to the outgrowths of the adjacent cells (Fig. 127, C). Atten- 

 tion should be fixed upon the form of the female gametangium and 

 the sac-like structure of the cystocarp because you will see these 

 features reappear in certain groups of the fungi. 



The spores formed from the growth of the gametospore are 

 finally set free and grow into plants resembling the gamete 

 bearing red algae but singularly these plants only produce 

 spores — never gametangia. These spores are formed in fours 

 in a single cell (Fig. 128) and therefore called tetraspores. These 

 spore-forming cells arise singly on the surface or in the tissues 



