i8o 



RESEARCHES ON FUNGI 



Fig 



, 104. — Ascobolus magnificus, one of the Discomycetes. Camera-lucida drawing, to 

 show hyphal anastomoses. A number of ascospores were shot on to cleared dung- 

 agar in a Petri dish where they germinated within 24 hours. The monosporous 

 myceha united to form a three-dimensional network, part of which is here shown. 

 Drawing made eight days after sowing the spores : a, b, c, and d, hyphae which 

 are elongating and which later would probably fuse with other hyphae ; e and 

 /, two hyphae each with its free end in contact with, and probably about to fuse 

 with, another hypha ; g, h, i, j, k, I, m, and n, eight hyphae which have anasto- 

 mosed with other hyphae and therefore have contributed to the transformation of 

 the mycelium into a three-dimensional network. Drawn by A. H. R. BuUer and 

 Ruth Macrae. Magnification, 120. 



Fig. 105. — Colletotrichum trichellum (Fr.) Duke (= V ermicularia trichdla Fr.). 

 Transverse section of one of the acervuli in a leaf-spot of an Ivy leaf {Hedera 

 Helix). The acervulus is mature. The cuticle of tlie leaf, a, has been ruptured 

 by the setae, and conidia are being produced on the conidiophores. Where 

 many conidia germinate on a leaf and infect it, the mycelia doubtless fuse 

 together and co-operate in the formation of acervuli. Drawn by Maud M. 

 Vuke {Trans. Brit. Myc. Soc, Vol. XIII, 1928, p. 162). Magnification, about 445. 



