MOULDS 323 



brownish-yellow in colour, and is distinguished from 

 Penicillium glaucum, which it otherwise resembles, by its 

 closely-felted mycelium, the hyphfe being scanty, ramified, 

 and segmented. It grows on gelatine, which quickly 

 becomes liquefied. According to Trelease, this mould is 

 identical with an alga, the Cladothrix dichotoma, which is 

 frequently found in dirty water. 



Oidium Lactis. — This mould grows as a white fur, and 

 is frequently found in sour milk and butter. The fibres 

 of the mycelium grow upwards, become segmented, and 



Fig. 32. — Oidium Lactis. 



support cylindrical conidia. The fungus grows on gelatine 

 without liquefying it, diffusing at the same time an odour 

 of sour milk. On agar it grows in the form of little stars, 

 which then overgrow the medium. In a thrust culture the 

 fibres of the mycelia are seen to permeate the medium. 

 Oidium lactis grows very readily in milk, which it does not 

 change in any special way. It is not pathogenic in man or 

 animals. 



Oidium Albicans. — The fungus causing the white patches 

 occurring on the mucous membrane of the mouths of infants, 

 known as ' thrush,' was formerly assigned to the group 



21—2 



