106 DISEASES OF CROPS. 



mature ergot gives rise to a perfect fungus bearing small 

 globular heads of a pale violet colour. Wben a longitu- 

 dinal section through one of the globular heads is 

 examined under alow power of the microscope, a number 

 of conceptacles are observed round the periphery of the 

 head (Fig. 41 A). These conceptacles, or flask-shaped 

 cavities, open outwards, and each contains a large number 

 of elongated asci (" sacks ") containing sporidia (Fig. 41 

 B and C). In England, these sporidia or spores are pro- 

 duced in June and July ; but the time for spore-formation 

 must necessarily depend upon the nature of the host-plant 

 and the environment.^ When the asci are ripe, the con- 

 tained sporidia are liberated. The latter fall upon the 

 young flowers of rye, where they germinate, ajid ulti- 

 mately give rise to ergots.^ The gradual formation of the 

 compact mycelium (ergot) of this fungus is at the expense 

 of the host-plant, which is greatly injured during the 

 latter stages of its growth. Ergots grow upon wheat, 

 barley, rice, and many grasses. 



Ergoted fodder produces abortion and ergotism in farm 

 animals. 



Prevention. — (1) A good system of drainage lessens the 

 liability of infection. (2) Farmers should take the pre- 

 caution to cut grass when in bloom, rather than in the 

 seeding state ; it will then be impossible for ergot to 

 appear. (3) In the case of ergoted grasses, a scythe 

 should be used for cutting off their " tops." The latter 

 should be raked together and burnt. 



' It is earlier in hot climates. 



^ M. Tanret {Comptes Beiidus [1889] , vol. 108) has recently iso- 

 lated a new substance from ergots, which he terms ergosterine 

 (C52H40O2). Ergosterine is an alcohol (monoatomio). 



