184 



RESEARCHES ON FUNGI 



freely, and which therefore have the best chance of liberating their 

 spores so that these may be carried off by the wind. 



It is true that the upper branches of branched Clavariae are not 

 truly vertical throughout but only more or less so ; but it must be 

 granted that the hymenium for the most part looks slightly down- 

 wards or horizontally rather than slightly upwards. This general 



position of the hymenium is 

 distinctly advantageous for the 

 liberation of the spores and 

 corresponds to what we find for 

 the hymenium in the Agari- 

 cineae, the Polyporeae, and the 

 Hydneae. 



That part of the surface of 

 compound Clavariae, e.g. Clav- 

 aria pyxidata and C. formosa, 

 which looks most directly up- 

 wards, i.e. the upper sides of 

 the forks where branching takes 

 place and the tips of the ulti- 

 mate branches, never produces 

 any hymenium or spores. Of 

 this I have been able to con- 

 vince myself by repeated obser- 

 vation with the microscope and 

 by the study of the position 



of spore- deposits. Upon examining a spore-deposit obtained by 

 laying a piece of a compound Clavaria flat on a glass slide in a closed 

 chamber, I always found that no spores had been deposited by the 

 surface layers of the fruit-body situated on the upper side of the 

 forks or covering the free tips of the ultimate branches, but that 

 spore-deposits had been yielded by all those surface layers which, 

 before the fruit-body had been gathered, had been vertically 

 situated or had looked more or less downwards. It is possible that 

 the non-production of a hymenium in the forks of the branches is 

 due to a regulating stimulus of gravity. Such a stimulus decides in 

 Sparassis crispa that the hymenium shall be developed only on 



FIG. 64. Clavaria (abietina ?), a branched 

 fruit-body with an upright habit. 

 Each larger branch has the form 

 of a compound club. Photographed 

 at Scarborough, England, by A. E. 

 Peck. Natural size. 



