232 MANUAL OF BACTERIOLOGY. 



consist of cells arranged end to end, making a thread-Hke 

 body called a hypha. The threads are matted together and 

 form a mycelium. Certain threads project upward from the 

 mycehum, and on them are borne spores. The arrangement 

 of the spores is characteristic in each variety of mould (Fig. 

 58). A group of organisms exist which have affinities both 

 with yeasts and mould-fungi. Some of them are pathogenic. 

 The form of infection of the mouth called thrush is due to a 

 fungus of this class, which is generally considered an oidium. 

 A chronic inflammatory affection of the skin (blastomycetic 

 dermatitis) is due to related organisms.* The sporotricha of 

 Schenck f which produces chronic subcutaneous abscesses, may 

 be mentioned here, provisionally. A number of skin affections, 

 such as tinea favosa and tinea trichophytina, are due to fungi, 

 which have some similarity to those above mentioned. 



Among the mould fungi, several species of aspergillus and 

 of mucor are pathogenic. Man, as well as the lower animals, 

 may be affected. In man the lungs may be involved in a 

 broncho-pneumonia (pneumonomycosis), usually due to asper- 

 gillus, and often secondary to some preexisting disease of the 

 lung. Mould fungi, especially aspergillus, may grow in the 

 external ear (otomycosis). The growth is usually superficial. 

 These fungi rarely produce lesions in other organs. 



* Ricketts. Journal of Medical Research. Vol. VI. 1901. Hyde and 

 Montgomery. Journal American Medical Association. June 7, 1902. 

 t Hektoen. Journal Experimental Medicine. Vol. V. 



