FITNOTION OF COLOUR AND SMELL IN FUNGI. 165 



The increasing strength of the distinctive odours which may 

 be observed in many fungi, from a young to a full-grown stage, 

 is a beautiful instance of adaptation to requirements. In the 

 early stage the presence of birds would be fatal to the 

 perpetuation of the species, inasmuch as the plant would be 

 destroyed before the spores were ripe. Hence an odour signal is 

 put up for the birds, only at the precise time when their presence 

 is indispensable. 



In contrast to birds, who come primarily for the animal life, 

 quadrupeds would mainly feed on the fungus itself, and in this 

 case colour and smell would be aided by a taste peculiar to the 

 animal who plays the part of host. In support of this it is 

 notorious, as any observer may test for himself, that, while many 

 fungi swarm with animal life, others are comparatively, if not 

 even perfectly, free. The former are the ones with repulsive 

 odour and taste, while the latter are usually sweet-smelling and 

 pleasant to the palate. 



LowKer forms of animal life than birds and quadrupeds 

 may be necessary to the existence of other fungi. Botanists 

 have long been acquainted with a class of fungi which seek the 

 common house-fly and other insects as their hosts, although the 

 precise dependence of the one on the other still awaits solution. 

 The flies which we so frequently see at this season, stuck to our 

 window panes, are simply the victims of a ravaging fungus, of 

 which the misty ring which surrounds the corpse represents a 

 multitude of reproductive bodies. When a spore has once found 

 its way into the living tissues of the fly it develops into a 

 considerable ramification of fine threads. Of these threads 

 those which appear on the outside of the fly bear reproductive 

 bodies at their free ends, which, according to a German botanist, 

 "are projected against the under surface of the bodies of other 

 flies, the only part at which penetration is possible," when they 

 at once develop into a branched system of threads similar to that 

 which bore them. 



Even the common slug may be necessary to the existence of 

 peculiar fungi. It is noteworthy -that, in cellars and pits, slimy 

 fungi and equally slimy slugs keep close companj ; and further, 

 wherever an earthy-smeUing fungus exists in our woods, there 



