CHAPTER III.— SPORES OF FUNGI. 89 



residue of protoplasm or glycogen-mass as the spores mature. I was unable to 

 determine their character more nearly, and can now only state that neither sugar nor 

 any acid reaction was ascertainable in the fluid contents of the asci of Peziza granulata, 

 P. Sclerotiorum, and Ascobolus furfuraceus. 



e. It is evident from what has now been said that, other conditions being the same, 

 the ejection of the spores must be hastened by a lateral pressure operating on the 

 ascus from without. This may readily be shown by experiment on isolated asci 

 placed in water beneath a cover-glass. In the living Fungi the asci stand very many 

 together in the hymenium usually with paraphyses between them, and there the 

 lateral pressure on the asci increases in part with the advancing growth, as new asci 

 are introduced between the previous ones, and in part with the addition of water ; 

 the hymenia in the Discomycetes which have paraphyses swell considerably in the 

 direction of their surface and in greater proportion than the tissue of their sporophores. 



f. All that has been said of the club-shaped asci may be applied in its main points 

 to the spherical sporangia of Protomyces macrosporus, which are formed free in 

 the water. The place of greatest extensibility, towards which the numerous ' spores ' 

 move, is in accordance with the shape of the sporangia a broad thin section or pit 

 in the wall, in the middle of which the fissure ultimately appears as a gaping slit. 



Section XXII. It has been already said that the asci of the Discomycetes 



of which we now proceed to speak, are arranged in superficial hymenia nearly 

 vertically to the surface and between numerous paraphyses of uniform height, 

 the extremities of which indicate the middle level of the hymenial surface. The 

 asci of a hymenium are not developed simultaneously ; during a period of time 

 which varies in different species new asci grow up one after another from beneath 

 between the paraphyses, while the older ones are ripening. When the asci approach 

 maturity and begin to enlarge each one elongates so much that its apex projects above 

 the surface of the hymenium, while its basal portion continues attached to the original 

 place of insertion. After ejection of the spores the ascus shrinks and the apex 

 usually returns to below the level of the hymenial surface. Where there are no 

 paraphyses, as in Exoascus, the same phenomena are observed with the modifications 

 which that difference naturally entails. 



In the hymenia of Peziza, Helvella, Morchella, Bulgaria, Exoascus, and the ma- 

 jority of the Discomycetes when they are ripening, the individual asci are constantly 

 discharging their spores in succession. If the Fungus is placed in a closed and damp 

 chamber and a glass plate is set in front of the hymenium, spores are soon found lying 

 usually eight together in a minute drop of fluid, and gradually the plate becomes thickly 

 strewed with them. But besides this gradual emptying of the asci many of the Dis- 

 comycetes have the peculiar habit of 'puffing' (Stauben), that is, of suddenly discharging 

 a whole cloud of spores, if they are shaken, or if the chamber in which they have been 

 kept is opened. The phenomenon is of course produced by the simultaneous 

 emptying of a number of asci. The Fungi on which my experiments were 

 chiefly made — Peziza Acetabulum, P. Sclerotiorum, and Helvella crispa — do not 

 puff when they are cultivated in a very damp and still atmosphere enclosed by a bell- 

 glass ; under these conditions only the continued gradual discharge of the spores 

 takes place. As long as the Fungus remains shut up in the damp atmosphere no 

 amount of shaking will cause it to puff, whether it is kept in the dark or in the 

 light of day, or is suddenly brought from the dark into diffuse or direct sun- 

 light ; but it puffs as soon as it is removed from the damp chamber into a dry 



