FUNGI. 



19 



Smith, where, on one and the same pileus, were a 

 normally-orientated and two inverted caps with rudi- 

 mentary stipes. He also figures another case in an 

 Agaric with a perfectly central, single, stalked inverted 

 cap, the whole structure concerned being so symmetrical 

 and even as to suggest proliferation rather than any 

 other phenomenon as a cause. 



The reason for the inversion of the cap in these 

 cases lies in the fact that, as a rule, similar surfaces 

 tend to come into contact, so that the secondary cap 

 must have its upper surface opposed to that of the 

 primary one and its hymenium and stipe directed 

 upwards. 



One of the most interesting abnormalities in Fungi 

 is that described by Chifflot as occurring in Aleuria 

 vesiculosa (Peziza lycoperdioides). For here we see an 

 instance, with which we are familiar in the foliage of 

 the higher plants and probably in the Agarics just 

 cited, of the working of the law of laminar inversion. 

 There occurred one to three extra caps centrally within 

 the primary one. The secondary cap had its hymenial 

 surface directed outwards, i. e. immediately opposed to 

 that of the primary cap. The hymenial surface of the 

 tertiary cap was normally orientated, so that the outer 

 surface of this cap was immediately opposed to the 

 corresponding surface of the secondary cap. There 

 was the commencement of a fourth cap whose 

 hymenium, in accordance with the law, was directed 

 outwards (PI. II, fig. 7). The simplest case of all 

 was that in which, instead of a secondary cap, a single 

 lamina grew vertically upwards from the centre, with, 

 as might be expected, a hymenium on both its surfaces. 



There may here be mentioned an isolated case illus- 

 trating a wholly distinct kind of proliferation, viz. that 

 of the entire margin of the pileus. Morot noted, in 

 Psalliota sylvicola, the occurrence of two " rings," one 

 within the other. A furrow ran all around the lower 

 surface of the cap a certain distance from the margin, 

 marking the former attachment of the upper " ring." 



