THE VIOLENT PROJECTION OF SPORES 145 



and many others, where only the last spore or the remaming two 

 or three spores were observed to be discharged, has convinced me 

 that the spores when liberated must be shot upwards for a little 

 distance before falling on to the hymenium. Doubtless the spores 

 were shot not quite vertically upwards, but nearly so. Hence the 

 various positions of the spores after settling. 



In the Coprini, it is exceedingly easy to observe the discharge of 

 spores from the basidia near the edge of a " deliquescing " gill. As 

 before, it is necessary to place the gill or piece thereof fiat in a closed 

 compressor cell to prevent too rapid loss of water and consequent 

 collapse of the basidia. With the low power of the microscope one 

 can then observe large numbers of basidia actively shedding their 

 spores (Plate II., Fig. 12). The phenomenon has quite a fascination 

 of its own. The spores, after disappearing from the sterigmata, very 

 frequently immediately reappear on the hymenium at some distance 

 from the basidia on which they have been developed. There is 

 no essential difference between the Mushroom and the Coprini in 

 regard to what one sees by using Method IV. Fig. 52 might 

 equally well apply to the basidium of a Coprinus coTnatus or 

 C. plieatilis. 



One fact which is yielded by the above observations, and has an 

 important bearing in explaining the mechanism of spore-discharge, 

 is that the four spores of a basidium are not shot off their sterigmata 

 simultaneously but successively. The succession of discharges in 

 the particular instance shown in Fig. 52 occupied twenty minutes. 

 There was an interval of a few minutes after each one before the 

 next took place. It is quite certain that usually the four spores of 

 a basidium are not discharged together. When one looks at the 

 hymenium of a Mushroom gill in face view, it is easy to observe that 

 many of the ripe basidia have only one, two, or three spores left upon 

 them. In many instances the successive discharge of two or three of 

 the spores was actually watched. In Coprinus comatus one can 

 make similar observations with great ease. I have watched hundreds 

 of basidia discharge their spores in this species, yet never once have 

 I seen all four spores of a basidium discharged together. Here, as in 

 the Mushroom, the four spores of a basidium disappear from their 

 sterigmata one by one, in the course of one or a few minutes. 



K 



