438 RESEARCHES ON FUNGI 



by Fitzpatrick ^ in August, 1914, at Six Mile Gorge, near Ithaca, in 

 the State of New York, growing on Polyporus perennis. It is the 

 only species of Agaricineae known to be parasitic on one of the 

 Polyporeae. 



Fitzpatrick remarks that, at Six Mile Gorge, there were 

 numerous fruit-bodies of Polyporus perennis but only a few 

 which were parasitised. Among his other observations were the 

 following : 



The parasitised fruit-bodies of Polyporus perennis give but little 

 evidence of the presence of the parasite, for they are normal in their 

 general appearance, show no trace of either hypertrophy or dwarfing 

 and, when seen from above, cannot be distinguished from fruit- 

 bodies which are unparasitised. The fruit-bodies of the parasite, 

 Claudopus subdepluens, are minute and occur in considerable numbers 

 about the mouths of the hymenial tubes and along the stipe of their 

 host-plant. An examination with hand-lens reveals that certain of 

 the hymenial tubes of the Polyporus in the immediate vicinity of 

 the fruit-bodies of the parasite are partially filled with the greyish 

 mycelium of the Claudopus. 



In Fig. 184, from below and twice the natural size, are to be 

 seen three or four fused pilei of Polyporus perennis ^ bearing over 

 one hundred fruit-bodies of the Claudopus. Of the Claudopus 

 fruit-bodies only about half a dozen are fully expanded, while the 

 rest are in various stages of development. The blurs in the photo- 

 graph are the stipes of the host fruit-bodies, which failed to come 

 into focus. In Fig. 185 the expanded fruit-bodies of Fig. 184 are 

 shown four times the natural size. 



The fruit-body of Claudopus subdepluens is described as follows. 

 Pileus at first convex, then expanded, minute, maximum diameter 

 1-4 mm., white, minutely tomentose, margin sulcate ; gills salmon- 

 coloured from the first, distant, adnate, edge quite entire ; stipe 

 white, lateral, curved, up to 2 mm. long, less than 0-5 mm. thick ; 

 basidia clavate, provided with 4 sterigmata ; spores angular, 



^ H. M. Fitzpatrick, " A Parasitic Species of Claudopus," Mycohgia, vol. vii, 

 1915, pp. 34-37. 



2 When the fruit-bodies of Polyporus perennis grow very near to one another, 

 the pilei frequently become confluent. Cf. these Researches, vol. ii, 1922, p. 81. 



