g8 RESEARCHES ON FUNGI 



fruit-bodies in the culture ranged in size between these extremes. 

 I observed the length of the spore-fall period in a number of fruit- 

 bodies of different sizes, and the results of these observations are 

 given in the Table below. 



The method of observation was as follows. Fruit-bodies were 

 chosen for study which happened to be coming up very close to the 

 side of the closed glass vessel in which they were contained. These 

 fruit-bodies, without their being disturbed in the slightest degree, 

 were then observed from without from the time their conical pilei 

 began to expand until all their spores were shed. The optical 

 apparatus used for observing the fruit-bodies through the glass side 

 of the container was sometimes a horizontal microscope (PI. IV, 

 Fig. 29, in Vol. I), sometimes a hand-held low-power objective 

 of a microscope, and sometimes a pocket lens ; and some large 

 fruit-bodies were observed merely with the naked eye. Certain 

 small fruit-bodies carne up so near to the glass side of the container 

 that with a low-power objective I was able to observe their black 

 spores as they fell from the giUs through the air ; but with more 

 distant fruit-bodies this could not be done. The spores are shed 

 from the fruit-bodies of Coprinus curtus in the same manner as from 

 those of larger Coprini such as C. comatus and C. atramentarins, 

 i.e. in succession from below upwards on each gill or, as the pileus 

 flattens, from the periphery of the pileus centripetally toward the 

 stipe. Spore-discharge does not begin until the pileus has become 

 almost plane. As soon as the spores begin to fall, a spore-free 

 zone is created all around the periphery of the pileus. This zone, 

 owing to the loss of its black spores, appears white when observed 

 either with a lens or with the naked eye, and it gradually extends 

 from the periphery of the pileus centripetally toward the stipe. As 

 soon as it has covered the whole of the hymenium spore-discharge 

 has ceased. The white spore-free zone on any pileus under observa- 

 tion began to be developed at a definite time and completed its 

 development at a definite time. These times were carefully noted 

 and the first was then subtracted from the last. The difference 

 gave the spore-fall period. The following Table records the results 

 of a series of observations made on seven fruit-bodies during the 

 morning of February 3, 1914. 



