The Molds 



45 



Aspergillus nidulans occasionally infects cattle. It is pathogenic 

 for laboratory animals, usually causing death in sixty hours. The 

 kidneys are found enlarged to twice their normal size, and show small 

 whitish dots and stripes of cell infiltration containing the fungi. 

 The heart muscle, diaphragm, and spleen may also be involved. 

 The liver usually escapes. It takes a large number of spores to' 

 infect. 



Aspergillus fumigatus. — This is a widespread and not infrequently 

 pathogenic form. Its most common lesion is a pneumomycosis, in 

 which the lung is riddled with small inflammatory necrotic and 

 cavernous areas containing the molds. Though of frequent occur- 

 rence in cattle it is but occasionally observed in human beings. 

 Sticker having collected 39 cases.* 



Fig. 14. — Muctjr mucedo. Different stages in the formation and germination 

 of the zygospore: i, Two conjugating branches. in contact; 2, septation of the 

 conjugating cells (o) from the suspensors (i); 3, more advanced stage in the 

 development of the conjugating cells (a); 4, ripe zygospore (6) between the 

 suspensors (a) ; 5, germinating zygospore with a germ-tube bearing a sporangium 

 (After Brefeld). 



Leber and others have observed keratitis following corneal infec- 

 tion by this organism. 



Aspergillus flavus is also pathogenic. 



Aspergillus subfuscus is also pathogenic and highly virulent. 



Aspergillus niger. — Pathogenic and found at times in inflammation 

 of the external auditory meatus. 



5. Penicillium. — These are common green molds, widely dis- 

 seminated throughout the atmosphere and frequent sources of 

 contamination of the culture-media in the laboratory. Moist bread 

 exposed to the atmosphere soon becomes covered with them. They 

 * Nothnagel's SpezieUe Path. u. Therap., xiv, 1900. 



