PUFFING 237 



Puffing. The normal method of spore-discharge from Peziza re- 

 panda under natural conditions is probably a more or less successive 

 discharge of ripe asci, the spore-discharge period lasting for some days. 

 A similar gradual emptying of the asci has been observed in other 

 Peziza?, in Helvella, Morchella, Bulgaria, Exoascus, &c. x When a 

 fruit-body of Peziza repa-nda was left undisturbed for some hours in 

 a damp-chamber it ceased to liberate its spores. The beam of light 

 showed that none of the asci were discharging their contents. 

 However, when the glass plate covering the culture vessel was 

 raised and the hymenium was rubbed with a match-stick or other 

 rod, a considerable number of asci burst almost simultaneously and 

 spore-discharge continued for at least an hour. According to De 

 Ba^ry, the simultaneous discharge of a large number of asci the 

 phenomenon known as " puffing " may be caused in Peziza 

 acetabulum, P. sclerotiorum, and Helvella crispa by shaking a fruit- 

 body, or by suddenly allowing a fruit-body which has previously 

 been kept in a damp-chamber to come into contact with dry air. 2 

 He further found that the bursting of isolated ripe asci when lying 

 in water can be brought about " by exposing them to the operation 

 of agents like alcohol and glycerine, which withdraw their water." 3 

 He came to the conclusion that loss of water causes puffing " by 

 altering the state of tension in each ascus either by lessening the 

 expansion of the lateral walls and so increasing the pressure of the 

 fluid contents on the place of dehiscence, or by lessening the power 

 of the place of dehiscence to resist the pressure which remains 

 unaltered." 4 Massee 5 has pointed out that this explanation is not 

 entirely satisfactory, " as fungi will often puff, after lying in a room 

 for some hours, if moved." In Peziza rej)anda I have found that 

 mere rubbing without change of atmospheric conditions was suffi- 

 cient to cause some of the asci to burst. The simplest explanation 

 of these two observations seems to be a mechanical one. One may 

 suppose that at any one time the hymenium of a mature sporocarp 

 contains a number of asci which have almost reached the critical 



1 De Bary, Comparative Morphology and Biology of the Fungi, Mycetozoa, and 

 Bacteria, English translation, 1887, p. 89. 



2 Ibid., p. 90. 3 Ibid. * Ibid. 

 6 G. Massee, British Fungus Flora, 1895, vol. iv. p. 4. 



