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XX\'II. Observations on the Cause of Ergot. Bi/ Mr. John Smith, A.L.S. 



Read November 6, 1838. 



1 HE substance called Ergot being a production vvliich has given rise to a 

 diversity of opinions, in regard to its nature and origin, and the more than 

 usual quantity this season on several species of Elymus and other grasses in 

 the Royal Botanic Garden at Kevv having attracted my attention, I was in- 

 duced to examine it, and I beg to lay the result of my observations before the 

 Linnean Society. 



Ergot is well known to be a black fungoid-looking body, seated within the 

 floret, and protruding beyond the glumes (in the manner of a spur) of many 

 species of grasses, especially the Rye. DeCandolle considers it as a fungus, and 

 refers it to the genus Sclerot'mm. Fries also includes it among fungi, giving 

 it the name of Spermoedia Clavus, with the following generic character : — 

 " Variable, rounded, entophytal, rootless ; of a fleshy, mealy, homogenous tex- 

 ture, with a rind concrete, scaly, or somewhat pruinose. Proper fructification 

 none." He concludes, however, by stating, that " it is only a morbid con- 

 dition of the grain of corn, not propagated by seeds, but generated by a par- 

 ticular combination of external influences ;" and observes that some consider 

 Ergot to be caused by the puncture of insects. I had paid some attention to 

 the subject for several years past, and from the circumstance of observing a 

 peculiar species of fly settling on the ergot-bearing spikes, I was led to sup- 

 pose that they were in some way instrumental in producing it ; but what more 

 particularly attracted my attention this autumn was, early one morning ob- 

 serving large drops of a brown-coloured liquid hanging from the spikes of an 

 Elymtis, which contained a number of full-grown ergots ; and towards the 

 apex of the spike, where the ergots were younger, I also observed nearly simi- 

 lar but more transparent drops. 



This liquid in either state was found to be viscid, and of a sweet taste ; and 



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