i9Ml thaxter— FUNGUS-PARASITES 237 



attachment to the host and a means of absorbing such materials 

 as are necessary for growth. In other words, the foot is also a 

 haustorium. , Among the Laboulbeniales, those forms which, like 

 Dimeromyces rhizophorus, perforate the host's integument, may 

 be assumed to derive their nutriment directly from the fluid 

 materials which surround their deeply penetrating rhizoids; in 

 fact this conclusion seems unavoidable. But that a very closely 

 allied species like D. coarctatus, which possesses a typical foot and 

 does not penetrate, although it grows under identical conditions 

 on a soft-bodied host, should use materials which are either of a 

 different nature or derived from a different source, seems not at 

 all probable. In the opinion of the writer, even those forms which 

 grow on spines or hairs or thin wing-membranes obtain their food 

 supply from the same source as do the penetrating forms, namely 

 from the circulatory system, which by diffusion or otherwise sup- 

 plies the structures mentioned in the living insect. There seem 

 certainly to be no differences in the vegetative characteristics or in 

 the peculiar fatty cell contents in any of the Laboulbeniales which 

 would suggest that the nutrition of these plants is not the same in 

 all cases. The assumption that the food material is obtained 

 directly from the circulation seems further supported by the fact 

 that individuals which grow nearer the circulatory centers, as for 

 example about the bases of the two anterior pairs of legs, or along 

 the chief circulatory channels, are usually larger and more luxuriant. 

 That any considerable portion of their food is derived from the 

 integument itself seems quite improbable in view of the host- 

 relations of the penetrating forms. An examination of the accom- 

 panying plates will show the presence, in most instances, of a 

 blackened footlike structure similar in a general way to that of the 

 Laboulbeniales, and in the writers' opinion these plants, also, may 

 be assumed to obtain their food materials from the circulatory 

 system through the medium of this haustorium. 



Among entomogenous Fungi Imperfecti, one other type has 

 been observed on living insects, which is not herewith included; 

 for the reason that, as yet, no definite spore-formation has been 

 seen in any of the several species examined. These plants consist 

 of colorless, septate, copiously branching filaments, which grow 



