24 



RESEARCHES ON FUNGI 



observed by Kohler * when he grew germ-mycelia of these fungi side 

 by side. 



So far as vegetative fusions between mycelia of different species 

 are concerned, as we have seen, the special observations of Reinhardt, 

 Laibach, Kohler, Forsteneichner, Matsumoto, and Davidson, 

 Dowding, and Buller have yielded results which are essentially 

 negative. A similar negative result was obtained by myself recently 

 when I paired mycelia of Pleurage conica and P. anserina in a 



hanging drop of cleared 



« U r> 



dung-agar ; for, whereas 

 numerous hyphal fusions 

 could be readily observed 

 between hyphae of P. 

 conica or between hyphae 

 of P. anserina, after a 

 prolonged and careful 

 search no hyphal fusions 

 could be detected between 

 a hypha of P. conica and 

 a hypha of P. anserina. 



In my field and la- 

 boratory studies of the 

 Hymenomycetes, I have 

 seen nothing to suggest 

 that in this group species-hybrids exist. In general, the species 

 of Hymenomycetes remain morphologically distinct from one 

 another without intermediate forms. Thus on unsterilised horse 

 dung in laboratory cultures several species of Coprinus, e.g. 

 C. sterquilinus, C. niveus, C. stercorarius, C. lagojms, C. curtus, 

 and C. ephemerus, often come up close together, yet their fruit- 

 bodies remain specifically distinct and never show appearances 

 which suggest that the haploid mycelia of two distinct species have 

 fused with one another and have given rise to a hybrid diploid 

 mycelium which in turn has given rise to a hybrid diploid fruit- 

 body. Brunswik 2 failed in attempts to cross Coprinus species, and 



1 E. Kohler, loc. cit., p. 511. 



2 H. Brunswik, " I. Untersuchungen iiber die Geschlechts- und Kernverhaltnisse 

 bei der Hymenomycetengattung Coprinus,'''' Goebel's Botanische Abhandlungen, 



Fiu 



12. — Fusions between sporidia of three 

 different species of Ustilago : U. Tragopo- 

 gonis, sporidia oblong ; U. anomala, sporidia, 

 biscuit-shaped with oil-drops ; U. Cardui, 

 sporidia spherical. From Kniep's Vbcr 

 Artkreuzungen bei Brandpilzen. 



