C K YPTOG AM I A 223 



same vicinity. Hence the conclusion, that if the sporules of 

 othei kinds be present in these beds, they do not grow, be 

 cause the soil is not suited to their growth. We are aware 

 that a contrary argument has been drawn from the above 

 named fact, and that because any quantity of the Agaricus 

 campestris, or edible Mushroom, may be produced by certain 

 conditions of soil, temperature and moisture, without sowing 

 the seeds, therefore Mushrooms cannot be the product of 

 seeds floating through the air, for were this the case, other 

 kinds besides the campestris would spring up, since the 

 Mushroom beds would be as liable to receive the poisonous, 

 as wholesome species. If we suppose that the sporules of 

 the first crop perpetuate their own species, then there is no 

 difficulty in accounting for a perpetual succession ; and there- 

 fore, under this restriction, the only doubt refers to the first 

 product. Now that the sporules of these plants exist every 

 where, and that they only lie dormant until circumstances of 

 soil, heat, arid moisture, cause them to vegetate, may be safely 

 inferred, or indeed is nearly certain, from the observations of 

 M. Fries, of Sweden, whose knowledge on this subject no one 

 will dare to deny. This naturalist says that the sporules ot 

 this tribe are so infinite in number, that in a single individual 

 of the species, (Reticularia maxima,} he counted above ten 

 millions. That these seeds are so small as scarcely to be 

 visible to the naked eye, and that when rising in the atmos- 

 phere they often resemble thin smoke. That besides being- 

 disseminated by a kind of evaporation through the air, they 

 are dispersed by the wind, by insects, elasticity, and adhesion, 

 so that it is difficult to conceive a place from which they can 

 be excluded. From all that has been said, we may fairly 

 conclude, that the notion of fortuitous, or equivocal produc- 

 tion, which has been employed to account for the appearance 

 of Mushrooms, is entirely without foundation, and has been 

 adopted from ignorance, or a limited view of the nature of this 

 tribe. And also, that in whatsoever situation we may observe 

 these productions, we may be sure that their sporules existed 

 there before, but that the conditions of heat and moisture, and 

 perhaps other circumstances unknown to us, had not been 

 previously adapted to their vegetation. Or, as it appears that 

 these sporules may be floating in the air, for aught we know, 

 constantly, during certain seasons, they may have been de- 

 posited only just in time to vegetate. Many other seeds, it 

 is well known, lie dormant for years, or perhaps for ages, un- 



