THALLOPHYTA— FUNGI 



71 



they are produced. The sporophyte rarely ooourring, it follows 

 that they generally arise upon the gametophyte. In most cases 

 they are small rounded bodies, each with its cell-waU. They 

 may be produced singly in a cell, as in the Sohizomyoetes, or 

 in groups of four or eight, as in the Ascomycetes. In most 

 Phycomyoetes they are produced in great numbers in globular 

 or elub-sliaped sporangia or gonidangia (fig. 823) borne upon 

 special aerial hyphse, termed gonidiophores. In other cases the 



Fig. 821. A. Branched mycelium of Ciistopiis with young oogonia, og, oq. 

 B. Portion of mycelium bearing oogonium, og, with the oospbere, o.s ; and 

 antheridium or pollinodium, an. c. Mature oogonium, with os, the 

 oospore. D. Mature oospore. E. p. Formation of swarm-spores or zoo- 

 spores, G, from the oospores. /, i. Protruded endospore. After De Bary. 



spores are never in a sporangium, but are produced from 

 special hyphae by a process of abstriction or budding, leading to 

 the formation of strings of them, called stylogonidia [fig. 824). 

 Usually each spore ultimately becomes free. In one group, the 

 Uredinese, they remain together, in number two or more 

 (fig. 825), each of which can germinate while associated with the 

 others. These are sometimes looked upon as compound spores, 

 though each one is actually independent. This form is known 

 as a teleutospore. There is some dpubt a? to whether the 



