136 CLASSIFICATION OF THE MICRO-ORGANISMS. 



into the stalk ; spores colourless, very small, longish, 

 3 n long, 2 fjb broad. 



These two forms were obtained from ordinary white 

 bread kept at the body temperature. M. corymbifer 

 was also found by Hiickel in a plug in the auditory 

 meatus in man. When the spores are injected into the 

 blood stream in rabbits, both forms cause the death of 

 these animals after 48 72 hours, the incubation period 

 lasting 24 hours. On post-mortem examination fungus 

 mycelium is found chiefly in the kidneys, then in the 

 mesenteric glands and in Peyer's patches, more especially 

 in the lower part of the small intestine. The patches 

 show marked swelling and ulceration. Injections into 

 the peritoneal cavity also give rise to the same symptoms. 

 Dogs are entirely immune, while aspergillus spores pro- 

 duce disease, though only when present in large numbers. 

 It is also noteworthy that of the mucor forms only those 

 can exert a pathogenic action which grow well at the 

 body temperature. On the other hand it is evident that 

 this is not the only or a sufficient condition for the 

 malignant action of mould spores on warm-blooded 

 animals, for M. stolonifer also flourishes well at high 

 temperatures, but the spores of this fungus cultivated at 

 that temperature cause no effect when injected. 



In Aspergillus glaucus, Oidiurn lactis, Mucor mucedo, 

 and Mucor racemosus, we have four of the most widely 

 spread mould fungi, with which every one who works 

 with pure cultivations of fission or mould fungi becomes 

 unintentionally acquainted. There is only one fungus 

 which excites even greater interest from this point of 

 view, because it occurs extremely frequently, and is the 

 The common most common mould fungus : this is the pencil mould, 

 P en ^ c ^ um ) which belongs to the tuberaceae (order : 

 Ascomycetes). 



The higher form of fructification, a kind of truffle, is only 

 observed very rarely, and under special conditions of cultiva- 

 tion. It presents the appearance of a small yellow, sand-like 



