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LIFE HISTORY OF CLAVICEPS 



pistil, rapidly forming spores (Fig. 154, A, B) and exuding a 

 sweet slimy juice, honey dew, which is eagerly eaten by flies. In 

 this way the spores are carried away to infest other plants. The 

 mycelium finally completely absorbs the substance of the grain 

 and grows into a hard blue-black body several times larger than 

 the grain (Fig. 153.) This body, known as the sclerotium, re- 

 mains dormant during the winter and in the spring develops 



Fig. 152. Other common forms of the Spheriales: A, habit of Hysteria- 

 graphiuni, on a dead twig. 5, ascocarps enlarged. C, ascus enlarged, show- 

 ing character of ascospores. D, Daldinia. E, section of the same, showing 

 that the stroma forms a concentric stratum of ascocarps, as, each year. F, 

 Xylaria. G, the same with branch cut off to show the layer of ascocarps 

 on the periphery of the stroma. 



a stroma that assumes the form of rose-colored stalks bearing nu- 

 merous ascocarps arranged in globular heads (Fig. 154, C, D). 

 The ascospores germinate in the spring and infest the flowers of 

 the grain. The Chinese wonder, Cordyceps, is a related para- 

 site that attacks caterpillars, larvae of beetles and truffles. In 

 the case of the forms living upon insects, the parasite does not 

 usually appear until the spring, when they are in the pupa or 

 cocoon stage. At this time, the mycelium which flourishes in 

 the tissues of the host, sends up club-like bodies (Fig. 155), 

 that bear the ascocarps as in the case of the ergot. 



