of lower forms of Vegetation. 191 



distributed to almost any distance. Whilst I admit the 

 spores to be the reproductive bodies, I dissent from the 

 latter conclusion, which seems very doubtful, as far as obser- 

 vation will carry us in this difficult subject. I am inclined to 

 think the spores of Agarics at least arc not generally dissemi- 

 nated far from the spot on which the plant which produced 

 them grew. 



I have always found Agarics which bear spores of a colour 

 easily seen, the Leucosporidia for instance, shed them under- 

 neath the pileus ; and that the grass, &c. is covered with the 

 spores only immediately around and beneath the plant, to 

 which they adhere, and are not blown away as soon as shed. 

 It will be said this must necessarily depend upon the atmo- 

 sphere, whether the air is still or not ; but the generality of 

 Agarics lie very close to the ground, and the expansion of 

 the pileus, extended like an umbrella, must, I think, even in 

 windy weather, prevent any great current of air from passing 

 under it. Perhaps this w'ill be thought over-refined reason- 

 ing, but the following facts seem to countenance it. Particu- 

 lar species appear annually on the same spot of ground, and 

 do not w'ander away from it ; thus Ag. nebularis, Batsch, grows 

 every autumn at one corner of Leigh Down, and does not 

 spread from this locality. Ag. personatus. Fries, I have seen 

 every autumn in the same situation for several years. Ag. 

 oreades grows in eccentric circles, one circle exteriorly to that 

 of last season, which would scarcely be the case if the sporules 

 of this species were scattered about by the wind ; but single 

 individuals do occasionally occur : no doubt Ag. oreades is 

 propagated in these circles by underground mycelia, but this 

 circumstance does not affect the argument. The stump of a 

 tree immediately under a plant of Polyporus igniarius wall be 

 seen densely dusted with sporules, showing that these fall near 

 the spot occupied by the parent plant. It would be easy to 

 multiply instances of the regularity Avith which Fungi appear 

 in the same spot, but these are enough ; and from them I 

 infer that the dissemination of the spores of Fungi through 

 the medium of the atmosphere has been greatly over-esti- 

 mated. Taking into account the number of species of Fungi, 

 and the great quantity of sporidia which each plant gives 

 out, it seems to me the atmosphere must contain so many, 

 that they would certainly be detected in it before this time, 

 and yet none have ever been observed. The method of 

 making what is called mushroom-spawn is too well known to 

 need description, and every exhausted hot- bed will produce 

 plants of Ag. campestris : how did the germs of these plants 

 get there ? It is answered, through the air : this has been con- 

 sidered before ; besides, the mycelia will be found in the com- 



