234 



SPECIFIC MICRO-ORGANISMS 



tuberculosis. Fragments of the mycelium are found in the spu- 

 tum. Doubtless the human disease is contracted from the birds 

 in these cases. This mold has been found as the apparent cause 

 of inflammation in the auditory canal in a large number of cases 



and in the nasal fossae in a few in- 

 stances. Various other mammals are 

 susceptible to inoculation and natural 

 infection has been observed in horses, 

 cattle, sheep and dogs. 



Many other species of pathogenic 

 aspergilli have been described, of less 

 frequent occurrence than A.fumigatus. 

 Penicillium crustaceum (glaucum) 

 is the commonest contaminating mi- 

 cro-organism met with in the labora- 

 tory, and is probably the most widely 

 distributed mold. Ascospores, similar 

 to those of Aspergillus glaucus have 

 been observed, but they are rarely 

 produced. The aerial fruiting hypha 

 (conidiophore) is erect, septate and 

 branched at the upper end like a brush. 

 At the end of these branches are bot- 



FIG. 92. Pemcillmm crusta- 

 ceum. Conidiophore^ with verti- tie-shaped stergmae from which the 



conidia are constricted off. The 



comdia. XS4C. (From Jordan growth IS at first white and then It 

 after Strasburger.) 



becomes blue-green, the development 



of color beginning at the center. Penicillium crustaceum, or at 

 any rate a certain variety of it, is an important agent in the 

 ripening of Rocquefort cheese. It is not pathogenic, but the 

 extracts from cultures of some varieties are poisonous when in- 

 jected into animals. It is possible that several distinct species 

 have been included under this one name of Penicillium crustaceum. 

 Claviceps Purpurea. This is a fungus parasitic upon rye 

 and a few other plants. The spores gain access to the flower of 



