180 



It appears from the experience of the writer, that the lower 

 leaflets show a good deal of movement and that such movement 

 is due to the rapid wilting of the leaf. There is a curious feature 

 of the phenomenon, however, in the fact that the lessening of the 

 distance between the leaflet tips is not due to a general curvature 

 in those parts, at least in the early part of the process, but rather 

 to a more local, and therefore stronger, curvature at the base of 

 each leaflet. 



The matter would seem not unworthy of further examination. 

 We still are unable to answer the curious in regard to the origin 

 of the specific name; nevertheless, that the leaf is "sensitive"' 

 appears doubtless true. "Squeezing the stem " has, however, 

 nothing to do with it. 



Spore Expulsion in Webera {Diphysciuni) sessilis. — The peculiar,, 

 dorsiventral form assumed by the sporogonium of this plant is, 

 according to Goebel, assumed under the influence of one-sided 

 illumination. This was shown by cultivating the young sporo- 

 gonia, which are radially symmetrical under appropriate condi- 

 tions. The same author explains the form of this organ ideo- 

 logically as an arrangement by which the dissemination is facili- 

 tated by falling raindrops.* 



By tapping the upper side of a dry ripe capsule with a pencil 

 point the action of the raindrop falling upon it may be imitated. 

 In this way I have been able to see a puff of spores shot out 

 very rapidly to a distance of two inches. Doubtless the natural 

 conditions result still more favorably. The behavior is sufficiently 

 striking, however, as it stands. 



A KEY TO THE NORTH AMERICAN SPECIES OF 

 CORTINARIUS.— lit 



By F. S. Earle 



Inoloma 



I. Lamellae at first white or pallid. 2. 



Lamellae at first violaceous (as also the stipe and cortina). 4. 



Lamellae at first yellow, red, or cinnamon. II. 



* Organography (translation), p. 237. 

 f Continued from page 172. 



