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XXVII. Observations on the Cause of Ergot. By Mr. Joun a A.L.S. 
Read November 6, 1838. 
THE substance called Ergot being a production which 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 Kew 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 Sclerotium. 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 
Elymus, 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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