Ch. X] THE SAC FUNGI 447 



The majority of Red Algae show a remarkable specializa- 

 tion of the cystocarp formation. Thus in Polysiphonia, a 

 small dark, purple form common on our coasts among the 

 Rockweeds (Fig. 311), three kinds of plants are produced, 

 vegetatively similar but developing respectively tetraspores, 

 antheridia, and procarps. In course of development the cells 

 of the procarp form curious unions with contiguous cells, 

 though apparently these unions are purely of nutritive 

 nature; and the cystocarp does not remain naked as in 

 Nemalion, but becomes inclosed in a flask-shaped cover 

 developed from the subjacent tissues, as anticipated in Coleo- 

 chcete (page 423). Moreover, in this form, a regular alterna- 

 tion occurs between the sexual and the tetrasporic plants, 

 providing a case in which the two generations are vegeta- 

 tively alike (Fig. 361). 



There are many genera of beautiful forms of Red Algae, 

 some of which possess names, — Dasya, Ceramium, Cal- 

 lithamnion, Rhodomela, Delesseria, as graceful in their way 

 as the plants in theirs. These in fact are the beautiful "Sea 

 Mosses" which are favorite objects of collection by visitors 

 to southern sea shores. 



Ecologically the Rhodophyceae are typical divided thalloid 

 hydrophytes. Phylogenetically they represent a highly 

 specialized branch of the Algae, rather divergent in the 

 higher forms, but derived no doubt from some of the Green 

 Algae, probably not far from the Coleochaete group. They 

 represent the very highest development in the Algae, but 

 gave origin to nothing higher, unless possibly to some of the 

 higher Fungi (page 455). 



Class 9. Ascomycetes: the Sac Fungi 



(Part of Eumycetes) 



The groups of Fungi earlier described, — Bacteria, Myxo- 

 mycetes, and Phycomycetes, — bear close and obvious re- 

 lations to groups of Algae, of which they seem clearly to 

 represent hysterophy tic offshoots. There remain two greater 



