8 



RESEARCHES ON FUNGI 



the Sclerotinia to grow toward the Mucor hyphae, to wind about 

 them so as eventually to hide them in hyphal cylinders, to lay 

 their ends upon them, to kill them, and to absorb their contents. 

 No hyphal fusions were formed between the Sclerotinia and the 



Ftg. 2. — Reactions of a mycelium of Sclerotinia sclerotiorum (un- 

 shaded) to a Mucor mycelium (shaded). A, irregular branching 

 of the end of a Sclerotinia hypha after stimulation by an excre- 

 tion of a neighbouring Mucor mycelium. B, growth of a Sclero- 

 tinia hypha toward a Mucor spore. C, a spore and germ-tube 

 of Mucor attacked by short hyphae put out by a Sclerotinia 

 mycelium. D, E, and F, early stages in the envelopment of 

 Mucor hyphae by Sclerotinia hyphae. The Sclerotinia hyphae 

 apply themselves to the Mucor hyphae, but do not fuse with 

 them. Eventually, the Sclerotinia hyphae kill the enveloped 

 Mucor hyphae and absorb their contents osmotically. The 

 drawings copied by the author from Reinhardt's Das Wachsthum 

 der Pilzhyphen. 



Mucor, so that, at the points of contact, the former could only 

 absorb the contents of the latter by osmosis. 



Reinhardt, 1 working with Sclerotinia sclerotiorum, 8. trifoliorum, 

 and S. tuberosa, observed : that, when two mycelia of the same 

 species are paired in a culture, they grow toward each other, inter- 

 mingle, and form hyphal fusions with each other quite smoothly ; 



1 M. 0. Reinhardt, " Das Wachsthum der Pilzhyphen. Ein Beitrag zur Kenntniss 

 des Flachenwachsthums vegetabilischer Zellmembranen, , ' Jahrb. f. wiss. Bot., 

 Bd. XXIII, 1892, pp. 509-513, 



