CHAPTER X 



ENDOMYCETALES— EREMASCACEAE 



The principal line of development from a primitive foraa like Dipodascus, 

 has continued through the Eremascaceae to the Saccharomycetaceae, both of 

 which are probably very large families. Very few saprophytes have yet been 

 described in the Eremascaceae and not many more among the animal parasites 

 of this family, but there is a huge number of rather poorly described Ftogi 

 Imperfecti which probably will be found to belong to these families. 



Eremascaceae. — This family includes a few saprophytes on fruit juices 

 and several animal pathogens. Several of the genera have been poorly de- 

 scribed and apparently have not been recognized since their original pub- 

 lication. 



One of the primitive types is that of Eremascus fertilis on fruit juices 

 (Stoppel 1907, Guillermond 1909). The hyphae are often branched and con- 

 sist of long, narrow cells which are multinucleate (up to 15) in the vicinity of 

 the growing tip (Pig. 30, 1). In the older portions of the hyphae the cells are 

 uninucleate. About 5 days after transfer, two cells form copulation branches 

 in the region of their septa (Pig. 30, 2). The copulation branches do not 

 always arise simultaneously, and their length is often unequal; also both 

 processes may not arise from neighboring cells but from cells separated by 

 a small intermediate sterile cell. If they are not too short, they make a half 

 to a complete turn about each other. Those of Eremascus alhus coil helically 

 (Pig. 31). 



When the tips touch, the walls at the point of contact are dissolved, and 

 the two cells fuse. The nucleus of the hyphal cell divides, one daughter 

 nucleus remaining behind in the hyphal cell, the other migrating into one 

 copulation branch where it fuses with the nucleus of the other branch (Pig. 

 30, 4-8). The zygote in the bend of the copulation bridge swells up to form an 

 ascus which is abjointed from both copulation branches; its nucleus divides 

 thrice with the formation of 8 spores (Fig. 30, 9, 10), some of which occasionally 

 degenerate. Those remaining are liberated by disintegration of the asci. At 

 germination the spores swell to twice their former size, rupture the exospore 

 to form one or more germ tubes which, after repeated nuclear division, de- 

 velop to hyphae. 



Besides this normal development, occasional cases of parthenogenesis 

 occur; two copulation branches may swell to asci without fusion. A copula- 

 tion branch which fails to find a mate may develop parthenogenetically (Pig. 

 30, 10). In old cultures even the hyphal cells, though they earlier may have 

 put forth copulation branches, swell up parthenogenetically and form asci, 

 generally smaller than the diploid, but like the latter may have 8 spores, some 

 possibly aborted (Pig. 30, 11-U). 



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