Report on Botany. 



163 



cult to master. Aside from the mere matter of numbers, 

 the species in such genera seem more subject to variation 

 than in others, and appear to run close to, if not into each 

 other. Thus it is in flowering plants with the genus Carex, 

 which of itself is a study of considerable difficulty, and one 

 capable of absorbing the whole attention. Aud yet, in 

 our state, there are not half as many species of Carex as 

 there are of Agaricus. Nearly two hundred and fifty spe- 

 cies of Agaricus have already been detected in this state, 

 and doubtless there are twice that number in the United 

 States. In the Epicrisis of Fries, nine hundred and eighty 

 species ane described. Probably no other botanical genus 

 contains as many species as the genus Agaricus. So nu- 

 merous are they, that when an uudescribed species is 

 found, it is not always easy to select an appropriate specific 

 name for it, to such an extent have the available names 

 been preoccupied. Indeed, it seems quite clear, that the 

 necessities of the case, will soon require that the subgenera 

 of this unwieldy genus be raised to genera. Some idea of 

 the difficulties experienced by the celebrated Fries, in his 

 early study of this genus, may be formed from his intro- 

 ductory remarks in his Systema Mycologicum. He says in 

 substance, when I commenced the study of this genus the 

 species were vague, the definitions inadequate, the descrip- 

 tions repetitious, and scarcely a tenth part of the synonymy 

 was accurately determined. Behold, candid reader, in this 

 work the fruits of the labor of ten years. 



The variations in the species are sometimes exceedingly 

 perplexing. Two or three common varieties of the fly 

 agaric, Agaricus muscarius, are so well marked as to sug- 

 gest the question of their specific distinction. They vary in 

 color, in the character and consistency of the warts, and 

 especially in size, the pileus being sometimes one inch 

 across, sometimes ten ; the Ktem varying from one fourth 

 of an inch to nearly two inches in diameter. Equally 



