Simple Plants 213 



There is an infection in the skin, usually remaining localized there, 

 but it may invade the circulation and cause lesions in other parts of the 

 body. 



The blastomyces occur in human tissues only, as small round bodies 

 with granular protoplasm, and with thick hyaline capsules. They mul- 

 tiply by budding only in human tissues, but in cultures they may either 

 develop mycelia or grow by budding or do both. They may be numerous 

 in the lesions which they produce, or few and hard to find. 



They produce a fairly strong toxin. 



Aspergillus fumigatus (Fig. 103) is an example of the pathogenic 

 ascomycetes. It is a fungus widely distributed, usually as a harmless 

 parasite, having been found in the auditory canal, nose, and throat. 



In birds and in cattle, and more rarely in dogs, aspergillus may cause 

 lesions of the lungs, resembling tuberculosis, and of late years a good 

 many cases have been reported in man, particularly pigeon keepers and 

 hair sorters. In the majority of these cases the infection is secondary 

 to some long-standing affection of the lungs, though it also causes a 

 primary lesion resembling broncho-pneumonia, usually quite serious. 

 The patient coughs up a grayish-brown mass the size of a bean made 

 up entirely of mycelium and spores. 



Oidiomycosis (granuloma coccidioides) is the term applied to the 

 lesions produced by an oidium. In the past this organism has been 

 called immities, coccidioides, etc., but it is not yet definitely classified 

 by botanists. Infection with this organism is rare and is confined almost 

 exclusively to California. The disease is practically fatal. 



The oidium occurs in human lesions in the form of spherical bodies 

 which may reach a size of thirty microns. They consist of an irregularly 

 staining mass of protoplasm enclosed within a double contoured capsule 

 which is occasionally covered with prickles, or even long spines. The 

 organisms multiply in tissues only by endosporulation, never budding. 

 The spores may number as high as a hundred or more. They are 

 liberated by the bursting of the capsule. The number of parasites in the 

 lesions varies. The parasites may be many or few and hard to find. 

 In cultures the oidium grows as long septate branching hyphae. In time, 

 spores develop in the ends of the hyphae and are infectious. To inocu- 

 lated animals, the hyphae, themselves, are not infectious. 



The lesions produced by oidium often bear a close resemblance to 

 those caused by the tubercle bacillus, and have probably been mistaken 

 for them more than once on histologic examination. If the organisms 

 are few in number, a cheesy region may be formed, and if numerous, 

 even abscesses and ulcers. 



Blood and lymph streams seem to carry the organism so that it is 

 widely distributed. It is as likely to be found primarily within, as upon 

 the skin of the body. 



Like the tubercle bacillus, oidium involves the same organs ; lungs, 

 lymph-nodes, adrenal glands, meninges, seminal vesicles, etc. 



