YEASTS AND TORUL&. 121 



each of these, an oval body, the spore is formed, and this 

 becoming free, can give rise to a new individual. 



(2) Penicillium Glaucmn. This is perhaps the most 

 common of all the fungi met with in bacteriological work. 

 It is the common green cheese mould, and its spores are 

 practically omnipresent. The mycelium is like that of the 

 aspergillus. Perithecium formation takes place, but the 

 commonest mode of reproduction is by gonidia (vide Fig. 

 39 D). A filament (called a fruit hypha) grows out, and at 

 its end breaks up into a number of finger-like branches. 

 On the point of each of these a flask-shaped sterigma is 

 developed. On the end of this a row of oval spores 

 appears. These break off, and can give rise to new 

 individuals. 



Yeasts and Torulse : Saccharomyces, Torula, Myco- 

 derma. These are of the greatest importance, of course, in 

 brewing and baking. They only concern us as being of 

 not uncommon occurrence in the air. They consist of 

 round or oval cells usually many times larger than bacteria. 

 They often reproduce themselves by budding (vide Fig. 

 39 E, F), a portion of the protoplasm protruding, and finally 

 being cut off to form a new individual. Endogenous 

 spore formation also occurs (vide Fig. 39 G). Many of the 

 torulae, when growing in colonies, are brilliantly coloured. 

 What their true morphological relationships are it is difficult 

 to say, but they present many analogies to the oidia of 

 such forms as oidium lactis. 



A knowledge of the above type forms will enable the 

 student to recognise the more common fungi as such, when 

 they present themselves to him. For further information on 

 this group he is referred to De Bary's book on The fungi. 

 Certain fungi closely related to the above are pathogenic 

 agents. Some aspergilli have been found to grow in the 

 animal tissues and to produce death, and to the fungi also 

 belong the saprolegnia ferax (the cause of salmon disease), 

 the tinea tonsurans, and the Achorion Schoenleinii. 



