138 NON-PATHOGENIC MICRO-ORGANISMS. 



torulae, when growing in colonies, are brilliantly coloured. 

 What their true morphological relationships are it is diffi- 

 cult 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 a 

 disease of salmon), the tinea tonsurans, and the Achorion 

 Schoenleinii. 



