294 WiscoNsiK State Horticultura.l Society. 



In all cereals to some extent, but especially ia the rye, may 

 frequently be found a fungus which has long been known under 

 the name of Ergot {Claviceps 'purj^urtd). Like the corn smut, 

 this plant attacks the young grain and causes it lo assume a very 

 much enlarged form, protruding far beyond the husks and re- 

 sembling a cock's spur, whence its common name "spurred rye." 

 The whole enlarged mass is made up of hard mycelium, on the 

 surface of which the conidial spores are borne. The fungus may 

 exist in this indurated form for a long time without further de- 

 velopment, but when these ergot grains fall upon moist earth, 

 sprouts soon proceed from them which form club-shaped heads at 

 their extremities, in which spores of the second form are produced 

 in little sacs. These different forms were for a long time consid- 

 ered distinct species; but the hard state, that in which ergot exists 

 as sold in the shops and used in medicine, is only a form which 

 many fungi have the power of taking on when they prepare for 

 a season of repose. Ergot is one of the most poisonous of the 

 smaller fungi. In several provinces of France and Grermany, 

 epidemics of nervous derangement, resulting in gangrene and 

 frequent loss of limbs and even of life, have been traced to the 

 consumption of this plant in the bread made from rye which was 

 largely spurred, the result of an extremely favorable season for 

 the growth of this pernicious fungus. 



It is to be presumed that no one species of plant has caused so 

 much suffering to the human family as Peronospora infestans^ or 

 Potato Rot, as it is called in common parlance. Those of you 

 old enough to glance back in memory to those fatal years for 

 Irish peasantry, when their almost sole source of sustenance was 

 swept from them by the ravages of the rot, can form an idea of 

 the influence even a microscopic fungus can exert over the com- 

 fort and civilization of the race. The potato rot is one of those 

 small microscopic fungi best known to the naked eye by its ter- 

 rible effects. Its first general appearance was in the year 1845, 

 when it was first seen in the Isle of Wight, and a few weeks after 

 was observed with great wonder and dismay by all growers of the 

 potato throughout Europe. It is a plant which flourishes only in 

 damp weather, and its prevalence depends much on the condition 



