XX 



INTRODUCTION. 



The Boletus ekgansf,. which was found in the hollow of an old elm 

 tree root, in Auguft, 1786, did not make its appearance there in 1787, 

 but this piefent year 1788, on the 28th of July, another fpecimen grew 

 in the felf fame fpot ; fo that this fpecies feems to be biennial in its 

 nature. 



Some fpecies of Fungi are fubject, from accidents, in foil, fituation, 

 and expofure, to vary much in point of fize : I have feen fpecimens of the 

 Lycoperdo?i bovijia, varying from the fize of a walnut to that of a child's 

 head, when the fmall, as well as the large fpecimen, had arrived at its full 

 extent of growth. 



July 18, 1788, the Agaricus latusS was brought me, in a ftate of un- 

 common luxuriance. The pileus meafured twenty-feven inches in cir- 

 cumference, the furface was waved, and the margin undulated; a gill of 

 the firft feries meafured three inches and two lines in length, and fome- 

 thing more than one inch in breadth; the ftem was near feven inches 

 high, and about four in circumference; the feeds were of a brown colour, 

 and fpherical. 



In September, 1787, I gathered a fpecimen of the Agaricus mufcarius, 

 which weighed thirty-one ounces and upwards, though the lower part of 

 the item and the root were wanting. Happily however, this inequality 

 of fize is not very productive of error in the detection of fpecies ; for the 

 fubftance, texture, conftituent matter, and generally the colour too, are 

 often exactly fimilar, and undergo the fame mutations in the fmaller, as 

 in the larger fpecimen. 



In regard to the items of Agarics, the circumftances of folid and fiftu- 

 lar, mould be attended to with caution, before they can be properly ap- 

 plied as difcriminative characters; becaufe in many fpecies the item is 

 folid in the firft ftages of growth, but becomes fiftular, by degrees, when 



the plant arrives to its perfect ftate ; and, in the progrefs of decay, be- 

 comes 



/ Tab. 76.— £ Tab. t. 



