HEMIASCOMYCETES 141 



even the hyphal cells, though they earlier may have formed a copulation 

 branch, swell up themselves parthenogenetically to asci (Fig. 85, 12 to 

 14), which are generally smaller than the diploid, but like the latter, 

 may have eight spores or some spores may abort. 



From the type of Eremascus fertilis, there are two developmental 

 series, one includes isogamous forms like E. fertilis, the other heterog- 

 amous forms. Both, however, may develop parthenogenetically. 



In the isogamous series there may be directly connected to E. fertilis, 

 the Endomyces fibuliger, originally isolated from spoiled bread. Its hyphae 

 are always uninucleate, and show (in contrast to Eremascus fertilis 

 a tendency to disintegrate into oidia which develop to a sprout mycelium. 

 Furthermore, the hyphal cells also may proceed to sprouting (Fig. 87, 8). 



This development from sprout mycelium is apparently connected 

 with an extensive adaptation of the fungus to starch and sugar-containing 

 media: thus Endomyces fibuliger, in contrast to Eremascus fertilis, is 

 able to ferment sucrose and some monosaccharides. Wherever the 



Fig. 86. — Eremascus albus. Development of copulation branches and ascus. ( X 600 ; 



after Eidam, 1883.) 



budding cells arise on aerial mycelium, the diameter is smaller and the 

 wall somewhat thicker than in the submersed sprout cells. They are 

 then very resistant and survive a long period in temperatures up to 55° ( !. 

 Biologically, they apparently possess the significance of gemmae and, 

 because of the exogenous formation, may be designated as conidia. 



As in Eremascus fertilis, every two cells form copulation branches 

 which may approach each other; only very rarely however, after the 

 dissolution of the wall, are the two nuclei joined into a fusion nucleus 

 (Fig. 87, 1). Generally the copulation branches develop parthenogenet- 

 ically, even when the separating walls are temporarily dissolved (Fig. 

 87, 5). As an exception, a pseudogamous anastomosis of two sprout 

 cells may occur in which one changes to an ascus (Fig. 87, 2 to 4). 



In a large number of cases, no copulation branches are formed but 

 the asci, like the sprout cells, arise as lateral outgrowths of the hyphal 

 cells (Fig. 87, 6 and 7) ; then, however, they are three to four times larger 

 than the ordinary sprout cells. Occasionally they arise from ordinary 

 hyphal cells by swelling, or from swelling sprout cells. When they 

 begin to appear the formation of sprout cells slows up, but does not 



