MUTATIONS OF THE FUNGI. 117 



will abound, and then years may intervene and 

 not a specimen be discovered. In 1825, a little, 

 gray puff-ball (lycoperdon cinereum), about the 

 size of a large pin's head, abounded, covering 

 patches of grass in all our fields, looking like froth, 

 and in decay, when discharging its seed, like a 

 spongy curd; though it had not been observed, 

 not having vegetated, or very sparingly, for up- 

 wards of ten years. Others, again, particularly the 

 ligneous ones, remain permanently fixed for a long 

 period. The fingered clavaria (clavaria hy poxy- 

 Ion) may be found vegetating on the stump of an 

 old hazel in the orchard for twenty years in suc- 

 cession. That this elegant race has attracted so 

 few votaries many reasons may be assigned. The 

 agarics, in particular, are very versatile in their 

 nature, and we frequently want an obvious, per- 

 manent character, to indicate the species, affording 

 sufficient conviction of the individual. The rapid 

 powers of vegetation in some will change the form 

 and hues almost before a delineation can be made, 

 or an examination take place, requiring nearly a 

 residence with them to become acquainted with 

 their various mutations ; and we have no method of 

 preserving them to answer the purpose of compa- 

 rison. These are all serious impediments to the 

 investigation of this class ; yet, perhaps, I may 

 with some confidence suggest, that any one, who is 

 so circumstanced as to afford the time, so situated 

 as to find a supply of these productions, and will 

 bestow on them a patient examination, will find 



