114 CLASSIFICATION OF THE MICRO-ORGANISMS. 



Fungus of 

 ergot. 



of grasses. The fungus develops in the first place on the bloom, 

 in the form of a conidia-bearing stroma, which looks like a 

 dirty white, cheese-like mass (sphacelia, see below). The 

 numerous conidia project from the bloom, and are covered 

 M r ith a saccharine sticky juice (honey-dew) secreted by the 

 fungus. The fungus is spread directly by means of the 

 conidia; the mycelium becomes gradually converted into a 

 black sclerotium, which assumes a horn-like form (1 3 cm. 

 long), projects from the bloom, and carries at first on its 

 apex the dead and dried remains of the mycelium, like 

 a cap of a dirty yellow colour. This sclerotium lasts during 

 the winter, germinates in spring on moist soil, and develops 



Fig. 5. Claviceps purptirea. 



A, sprouting sclerotium (c) with fruit-bearers (W). 



jB, longitudinal section of the upper part of a fruit-bearing hypha ; 



cp, perithecia more highly magnified. 

 C, section through a perithecium ; sh, external layer of tissue ; 



hy t network of hyphse ; cp, orifice of perithecium. 

 7), ascus torn and giving exit to the thread-like spores sp. 

 J'J, ear of rye with ergot c ; s, remains of the sphacelia. 



perithecial-bearing stromata in the form of small stalked red- 

 dish heads. The perithecia are embedded in the surface of 

 the head ; the spores are thread-like, unicellular. The sclero- 

 tium which has the form of a cylindrical, dark violet body 

 with long sulci, and is in its interior white or reddish, and 



