760 



FUNGI 



such short segments that sections of it resemble a parenchymatous 

 tissue of the higher plants. 



After being kept through winter and moistened, the ergot 

 germinates and sends up several fleshy-pink stalks at the end 

 of which are round heads or stromata {s, Fig. 257). 



Imbedded within the substance of the latter are a large 

 number of flask-shaped perithecia (n, Fig. 257), the narrow ends 

 of which have a small opening outwards. From the base of 

 the interior of the perithecia long club-shaped asci arise in 

 which are eight filamentous ascospores. 



Fig. 257. — I. Ergot sclerotium germinated ; J stromata (natural size). 

 2. Vertical section through a stroma ; « perithecia (enlarged 15 diameters). 

 d Asci from perithecia ; a ascospores ; b germinating ascospore (enlarged 

 about 380 diameters). 



The ascospores are ripe about the time when grasses and 

 cereals are in flower and are shot out of their asci and through 

 the openings of the perithecia into the air. They are readily 

 blown about by slight breezes, and after alighting on the flower 

 of a grass they germinate and penetrate into the base of 

 the ovary. The germ-tube feeds on the substances within the 

 latter and soon grows into a white closely-woven mycelium on 

 the outside of which are produced a number of short hyphze 

 bearing single small oval conidia. 



