VUILLEMIN'S CLASSIFICATION 95 



out in the first chapter, many fungi, in* addition to their spores mul- 

 tiply by the formation of oidia or yeast-like cells, by fragmentation 

 of the mycelium, or by budding. These have been differentiated 

 from conidia by the fact that the latter do not grow at once — they 

 must first imbibe water and germinate. But at least some of the 

 growth cells, although they may resemble conidia, are capable of 

 growing at once if separated from the parent mycelium. One may 

 find in some species all transitions between these growth cells and 

 conidia. So it happens that the same organism may be classified 

 in one genus by one authority, and in an entirely different genus 

 by some other writer, owing to different interpretations of the same 

 structure; for instance, the organism of thrush, now generally con- 

 sidered as a species of Candida, has been placed in half a dozen or 

 fnore genera. Moreover, the same fungus may form more than one 

 type of conidium, or may produce its conidia on more than one type 

 of fruiting body. Thus one of the causative agents of chromoblasto- 

 mycosis may produce conidia from flask-shaped conidiophores on 

 some hyphae and show branching chains of conidia from unswollen 

 conidiophores on others. Depending upon which spore-bearing ap- 

 paratus predominated, or which one was seen by or most impressed 

 the worker, the same fungus has been classified in the genus Phialo- 

 phora or in the genus Hormodendrum (Cladosporium). 



The classification of the Fungi Imperfecti followed by most my- 

 cologists is based upon the system proposed by Saccardo. Another, 

 quite different, classification was introduced by Vuillemin and his 

 system, or modifications of it, is much used in France, Italy, and 

 Latin America. Since so much of the literature on medical mycology 

 has come from those regions, this system cannot be ignored by the 

 bacteriologist. 



Vuillemin's Classification. Vuillemin divided the Fungi Imper- 

 fecti into three orders on the basis of the characters of the reproduc- 

 tive bodies. Later a fourth order, the Microsiphonales, was added to 

 include the actinomycetes, but more recently this order has been re- 

 duced to a family. Vuillemin's ^~ classification is based upon what 

 were then new interpretations of reproductive bodies. See page 7. 



CLASSIFICATION OF THE FUNGI IMPERFECTI (VUILLEMIN'S 



SYSTEM) 



Order Thallosporales, reproducing by thallospores. 



Suborder Blastosporineae, reproducing by blastospores. This group includes 

 the non-spore-forming yeasts and fungi with yeast-like forms, as Candida. 



