GERMINATION OF ASCOSPORES 



33 



Fig. 38. Germination of Asco- 

 spores in Willia anomala (after 

 Hansen). 



the 



A OD 



germination tube. This separates the ascospore by a transverse wall 



accompanied by a slight constriction. In this the germination of the 



ascospores does not differ from the method of multiplication of cells 



in this yeast which, as we have seen, 



generally occurs at the end of the cell 



by a process intermediary between bud- 



ding and transverse partition. 



Third Example, Willia: We have seen 



that the ascospores of the genus Willia 



present a special form. In Willia ano- 



mala they are hemispherical and are pro- 



vided with a projecting edge. (Fig. 38, 



a.) At the moment of germination, 



which has been followed by Hansen, the 



ascospore swells and during this its jut- 



ting out border disappears but remains for some time during 



early stages of budding. The asco- 

 spore eventually forms buds at dif- 

 ferent points on its surface. 



In Willia Saturnus the ascospores 

 are lemon-shaped and are girdled with 

 a projecting ring. The wall of the 

 asc generally dissolves before ger- 

 mination. This begins by a swelling 

 during which the projecting girdle dis- 

 appears or remains; then a series of 



39. Germination of Asco- buds is produced at various points on 

 spores m Wilua saturnus. 



the surface of the ascospore. In the 



course of budding, the projecting thread disappears. (Klocker. 1 ) 



A. In many cases germination is preceded, as has 



been stated in a foregoing paragraph, by a partheno- 



gamic copulation of the ascospores. These, during 



enlargement, unite two by two by means of a copu- 



lation canal. B. The fusion is incomplete and the 



zygospore which results germinates by budding on 



all points of its surface, by preference on the copu- 



lation canal. 



Fourth Example, Debaryomyces globosus and Schwanniomyces 

 ocddentalis. Both of these yeasts have peculiarly shaped ascospores 

 in which it is wise to describe germination. In D. globosus the 

 ascospore is round or globoid and enveloped in a warty wall. When 



1 Klocker, A. Eine neue Saccharomyces Art (S. Saturnus). Comp. Rend. 

 trav. lab. de Carlsberg, 6, 1903. 



B 



Fig. 



Fig. 40. Germina- 

 tion of Ascospores 

 in Debaromyces 

 globosus (after 

 Klocker). 



