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The Laboulbeniaceae, a New Family of Fungi. 



By George Massee, F.L.S. 

 {Read May 17 t/i, 1901.) 



It may be truly said that during the past twenty years, not- 

 withstanding the very large amount of valuable work produced 

 in the United States of America on botanical subjects generally, 

 those portions dealing with the Fungi and Myxogastres are in 

 many instances of an exceptionally high order of merit, and at 

 the present day there are undoubtedly a greater number of 

 mycologists resident in the TJoited States than in any other 

 country in the world. The reason for this is not far to seek ; 

 each of the numerous experiment stations under the direction 

 of the Board of Agriculture requires that one member of its 

 staff shall be an expert in the important science of vegetable 

 pathology, and this of course implies not only a sound knowledge 

 of mycology, but, in addition, the ability to conduct original 

 research. 



The object of this paper is to call attention to a very interesting 

 group of fungi, for a knowledge of which we are almost entirely 

 indebted to the researches of Dr. Roland Thaxter, Assistant 

 Professor of Cryptogamic Botany at Harvard University, U.S.A. 



Dr. Thaxter's pets, constituting collectively the family Laboul- 

 beniaceae, are individually always minute, measuring, as a rule, 

 less than one millimetre in length, and are remarkable in one 

 respect — that of being external parasites on living insects of 

 various orders, Coleoptera, more especially aquatic forms, being 

 mostly victimised, although these parasites are not wanting on- 

 members of other groups of insects ; they also occur sparingly 

 on white ants and acarids. The general appearance of these 

 fungi is described by Thaxter as follows. " When examined 

 in situ on the host insect they appear in general like minute, 

 usually dark-coloured or yellowish bristles or bushy hairs, pro- 

 jecting from its chitinous integument, either singly or in pairs, 



