MONOGRAPH OF THE LABOULBENIACK^E. 



247 



matter that I am wholly unable to explain. It is certainly not connected in any way 

 with matters of nutrition, and although it may be in part explained as resulting from 

 the fact that the spores are transferred while the sexes are in coitu, and the points of in- 

 fection are determined by definitely recurring motions of the legs or otherwise, this does 

 not seem sufficient to explain the constancy of the phenomenon. Peyritsch (1875), 

 calls attention to the fact that Sligmatomyces Baeri invariably occurs on the under 

 surface of the male and on the upper surface of the female host. Such a fact, if it 

 were true, would readily be explained in this way. My own observations, however, 

 clo not agree with those of Peyritsch in this respect, though this relative position may 

 perhaps be the more common. 



That certain types of. form are associated with certain types of hosts seems to be 

 a fact illustrated in a limited number of instances, — a well-marked case being afforded 

 by the species of Laboulbenia which are found on Clivina and its near allies, and 

 those which occur on Galerita and related forms. The species of Laboulbenia which 

 inhabit water beetles also furnish a case in point. 



Parasites of Laboulbeniacece. In examining a very large amount of material I have 

 been struck by the general absence of parasites attacking these fungi. A very 

 small number of such parasites do, however, occur, the most striking of which belong 

 to two forms of an apparently new genus of the Chytridinese, which grow externally 

 on species of Ceratomyces, possessing well-developed filaments and large appendicu- 

 late zoosporangia. The only other parasite which seems at all peculiar to the order is a 

 minute organism, perhaps a yeast, that often completely envelopes the appendages, 

 especially of species of Laboulbenia, assuming a characteristic semi-lunar form. The 

 same organism sometimes makes its way into the interior of the perithecium, filling it 

 and destroying its contents. 



Parasites associated with the Laboulbeniaceas, and, like them, attached to living 



insects, are more or less abundant ; and while the majority are animal in nature (bell 



animalcules, rotifers, etc.), there is one genus of fungi (?), unknown to me, which, 



though quite colorless, resembles some of the more simple chlorozoosporic algce. It is 



attached to the insect (and sometimes by accident to specimens of the Laboulbeniaceoe) 



by a slightly blackened base, and consists of about three superposed cells, the upper 



of which produces a small number of apparently non-motile spores endogenously, that 



escape through a terminal opening. 



The genus described as Devoea, 1 which is evidently not in any way " related to 

 » 



1 Lockwood, S. Fungi affecting fishes. Jour. N. Y. Microscop. Soc. Vol. VI., p. 67 (1890). 



