372 FUNGI RELATED TO THE YEASTS 



is situated at about 20 C. At this temperature the ascs appear 

 in about 72 hours. Like the conidia, the ascs are always formed in the 

 presence of air. They are able to appear in the same time and numer- 

 ous filaments may be found which form both ascs and conidia. They 

 form, as with Endomyces capsularis, at the ends of the filaments either 

 by budding, or by partition, followed by a separation of terminal units 

 which gives a chain of ascs. Sometimes they are formed by an inter- 

 calary unit. 



The formation of these ascs is of special interest because of the 

 anastomosis which takes place. In most cases the ascs are formed 

 without anastomosis, as in the two preceding species of Endomyces, 

 but in about half of the cases, the young bud destined to form an asc 

 anastomoses with a cell situated in the vicinity by means of a sort of 

 copulation canal. This phenomenon has been sufficiently described in 

 a preceding chapter. Let us recall, however, that the middle wall 

 that separates the asc from the cell with which it is anastomosing does 

 not disappear but persists in the copulation canal. Sometimes this 

 wall does disappear but even in this case there is produced no mix- 

 ture of the contents of the two cells. (Figs. 56 and 57.) Also we 

 should look on these anastomoses as traces of an ancestral reproduction 

 analogous to that of Eremascus fertilis, but having disappeared today. 



The ascs appear like large round or oval cells. They have but one 

 nucleus and do not possess karyogamy. They contain numerous asco- 

 spores which may vary from one to four, but usually four. The 

 ascospores are hemispherical and they are surrounded by a projecting 

 ring which makes them look like a hat. In this manner they are like 

 the ascospores of Willia anomala and Endomyces decipiens. 



Germination of the ascospores has been recently studied by Dom- 

 browski. The ascospores are provided with a double membrane, an 

 exosporium and an endosporium. At the moment of germination, 

 the ascospores take their usual form if in a young culture or become 

 globular if in an old culture; the exosporium opens up at any place 

 on the surface of the ascospore. These germinate indifferently either 

 to produce yeast-like bodies or to form a mycelium directly. (Fig. 160). 



The ascospores are incapable, as with Endomyces capsulatus, of 

 yielding ascs directly. The ascs are only produced when the mycelium 

 is well developed. Endomyces fibuliger develops quickly on most 

 media. In beer wort, after three weeks, it shows a dry scum formed of 

 mycelium, covered by numerous conidia which give it a farinaceous 

 appearance; in the sediment, yeast-like cells are formed. In course 

 of development, an agreeable aroma is given off with a feeble fer- 

 mentation. 



In wort gelatin, it develops with a dry farinaceous spot and brings 



