VARIOUS OBSERVATIONS 



fruit-bodies of any Boletus or species of Agaricineae with a centric 

 stipe varies about a mean in accordance with the law of continuous 

 variation, and the range of variation for most of the common species, 

 e.g. for Boletus edulis, 

 Amanitopsis vaginata, 

 Lepiota procera, and 

 Coprinus comatus, is not 

 very great, is roughly 

 recorded in most fungus 

 floras, and is well known 

 to field mycologists. How- 

 ever, in Coprinus lagopus 

 the range of size-variation 

 is of unusual extent, owing 

 to the fact that, besides 

 producing the familiar 

 larger fruit-bodies (Fig. 

 20, p. 71), this fungus 

 gives rise, under certain 

 conditions of nutrition, 

 to very small fruit-bodies, 

 some of which are less 



-*" 'l^^BV 



than one hundredth the 

 size of the larger ones. 

 These extremely small 

 fruit-bodies will be called 

 in what follows dwarf 

 fruit-bodies. Before these 



FIG. 28. An abnormality in Clitocybe nebu- 

 laris. The largest fruit-body bears at 

 its apex a normal fruit-body with a 

 centric stipe and another fruit-body with 

 a lateral stipe and an inverted pileus. 

 Found at Northwood, Middlesex, Eng- 

 land, in 1913, and photographed by 

 Somerville Hastings. About natural size. 



dwarfs are discussed in 



detail, an account of a method for obtaining well-developed 



fruit-bodies will be first described. 



At Winnipeg, when fresh horse dung is procured from a stable 

 and kept enclosed in a large crystallising dish in the laboratory, 

 it usually happens that, at the end of two or three weeks' 

 time, three or four species of Coprinus make their appearance 

 on the dung-balls. These species are : Coprinus lagopus, 

 C. curtus, (= C. plicatiloides of Vol. I), C. ephemerus, and 



