82 



Minnesota Plant Life. 



Ergot is of considerable commercial importance on account 

 of its tubers, which form certain alkaloids used in medicine. 

 Of fungus alkaloids there is a considerable group, of which 

 those in poisonous mushrooms, poisonous pore-fungi and er- 

 got-tubers are examples. Ergot in rye sometimes occurs in 

 sufficient quantities to poison persons or animals that eat the 

 grain and where rye-bread is a staple article of diet it is neces- 

 sary to remove the ergot-tubers before the rye is ground into 

 flour. 



Caterpillar fungi. 

 Very closely related 

 to the ergot is a small 

 group of fungi which 

 live parasitically in 

 caterpillars and other 

 insect larvae. Some- 

 times on mossy banks 

 one will notice a little 

 reddish-yellow, pimply, 

 club-shaped body ris- 

 ing up among the 

 mosses and an inch or 

 more in height. If 

 this is carefully pulled 

 out from between the 

 moss-plants it will be 

 found to spring from 

 the body of some dead 

 caterpillar or other in- 

 sect. The plant-body 

 of the caterpillar-fun- 

 gus grows within the 



tissues of the insect and forms there a tuber-body similar to 

 that of the ergot. From this a bud develops into the club- 

 shaped stem over the end of which, and covering the sides, 

 a layer of somewhat bottle-shaped fruit-bodies is produced. 

 One kind of caterpillar-fungus has its compound fruit-body 

 branched, so that the unfortunate caterpillar seems to be carry- 



FlG. 



I,eaf-spot disease caused by fungus. 

 After Halsted. 



