440 RESEARCHES ON FUNGI 



Claudopus subdepluens because he considered that it is closely 

 related to G. depluens described by Peck.^ The fruit-bodies of the 

 latter species, however, are distinguished from those of the former 

 by their much larger size, their lamellae being at first white, and 

 by arising not on another agaric but on the ground or decaying 

 wood from a saprophytic mycelium. Recently, Fitzpatrick has 

 expressed the view that Claudopus subdepluens may be identical 

 with Quelet's Leptonia parasitica.^ 



Fitzpatrick has attempted to solve the problem of the relation 

 of Claudopus subdepluens with its host Polyporus perennis. After 

 remarking that the only external evidence of a diseased condition 

 in the infected Polyporus is the presence of Claudopus mycelium 

 partially filling certain of the hymenial tubes close by the Claudopus 

 fruit-bodies, he continues as follows : " The sporophores of the 

 Polyporus produce their hymenium in the normal manner. Thin 

 sections made through the point of attachment of the stipe of the 

 parasite to the host disclose no marked derangement of the elements 

 of the latter. It is possible to trace to some extent the course of the 

 hyaline hyphae of the Claudopus among the deeper-coloured threads 

 making up the sporophore of the Polyporus. Some of these are 

 found ramifying on the trama of the host to a considerable depth. 

 It is possible that they extend through its stipe to the soil. The 

 presence of fruit-bodies of the parasite on the stipe furnishes some 

 indication of this.^ 



" The mycelium of the parasite is relatively small in amount, 

 and the hyphae of the two fungi lie in close contact and run 

 approximately parallel. Careful search fails to reveal any organs 

 of the nature of haustoria, and dissolution of the host hyphae by 

 enzymes excreted by the parasite appears not to take place. If any 

 such process occurs, the disintegration of the host is insufficient in 

 amount to be evident in thin, free-hand sections.* 



^ C. H. Peck, " New York species of Pleurotus, Claudopus, and Crepidotus," 

 Annual Report N.Y. State Museum, vol. xxxix, 1887, p. 68. 



2 In lift. Dr. Fitzpatrick informs me, however, that, since the stipes of his fruit- 

 bodies were distinctly lateral, he thinks the species must be included in Claudopus 

 and not in Leptonia. Whether or not the two species are identical seemc to me 

 very uncertain. I have therefore thought it best to treat them as distinct. 



3 H. M. Fitzpatrick, loc. cit., p. 35. * Ibid. 



