FOMES APPLANATUS 



139 



i.e. one eight-thousandth of the total number of spores shed by 

 White's large Fomes applanatus fruit-body in six months. 



(6) A large fruit-body of Coprinus sterquilinus, which was 

 investigated in the same manner as the fruit-body of C. comatus 

 already described, was found to have produced a total of about 

 100,000,000 spores only. 1 These, if left undisturbed, would have 

 been liberated in about eight hours. The total number of spores 

 liberated by a large Coprinus sterquilinus fruit-body in about eight 

 hours is only about one fifty-four-thousandth of the total number 

 of spores liberated by White's large Fomes applanatus fruit-body 

 in six months. 



(7) Finally, a large Giant Puff-ball (Calvatia gigantea] was 

 found to contain about 7,000,000,000,000 spores, 2 i.e. about 

 1,500,000,000,000 more spores than were liberated in six months 

 by White's large Fomes applanatus fruit-body. 



The data given above for the total number of spores produced 

 and the length of the spore-fall period for each species, together 

 with the results of calculations for the number of spores liberated 

 per day, are embodied in the following Table. The actual figures 

 can only be considered as approximately correct. 



Spore-discharge Data for the Giant Puff-ball and Certain Hymenomycetes. 



We may now ask : why is it that a large Fomes applanatus 

 fruit-body produces several hundred times as many spores as a 

 large Mushroom (Psalliota campestris) ? I believe that the answer 

 to the question is to be found chiefly in the fact that the area of 

 the hymenium of the Fomes fruit-body is far greater than the 



1 Vide infra, vol. iii, Chap. VIII, Coprinus sterquilinus, Section : " The Spores." 



2 These Researches, vol. i, 1909, pp. 85-86. 



