676 TRANSACTIONS OF SECTION K. 
The importance of violent spore-discharge lies in the fact that thereby 
the very adhesive spores are prevented from touching one another or 
any part of the hymenium whilst escaping from the fruit-body. Each 
spore is shot out more or less horizontally into the spaces between the 
gills, in hymenial tubes, &c. The horizontal motion is very rapidly brought 
to an end owing to the resistance of the air. In consequence of this, 
and also of the attraction of gravitation, the spore describes a sharp curve 
and then falls vertically downwards. 
The path of the spore between the gills, in tubes, &c., has been called 
the sporabola, and is remarkable in that it appears to make a sudden bend 
approximately through a right angle. When for any spore the terminal 
vertical velocity and the maximum horizontal distance of discharge have 
been determined, its sporabola becomes amenable to a satisfactory mathe- 
matical treatment. 
In the agaricinee there are two distinct spore-producing and spore- 
liberating types of fruit-body—the Coprinus comatus type and the mush- 
rcom type. These differ from one another in several structural and 
developmental details. 
In the Coprini ‘deliquescence’ is a process of autodigestion which 
renders important mechanical assistance in the process of spore-discharge. 
It was more especially studied in the case of Coprinus comatus. The spores 
on each gill ripen and are discharged in succession from below upwards. 
Autodigestion leads to the removal of those parts of the gills which have 
already shed their spores and thus permits of the continued opening out of 
the pileus. By this means the necessary spaces for the violent discharge 
of th® spores from the basidia are provided. The spores, after describing 
sporabolas, fall vertically downwards between the gills. On emerging from 
the pileus they are scattered by the winds. ‘ Deliquescence’ is in no way 
connected with the visits of insects to the fruit-hodies, 
2. The Destruction of Weeds in Field Crops by Means of Chemical 
Sprays. By Professor Henry L. Bonney. 
This paper cited the fact that spraying for the control of fungi and 
insects has developed but slowly along lines directed chiefly by simple 
trial experiments. There has been in this work but slight real investigation 
upon biological effects or relations either as affecting the host or the 
parasite. 
Noting that since he introduced the work of field-spraying for control 
of weeds in cereal crops the idea is being widely accepted and applied 
under greatly varying conditions of the crop, weeds, and season, the author 
called attention to the great possibilities involved in the process, both for 
crop improvement and crop production. 
It calls for no mere spraying of a few vegetables, a vine, or a few 
trees at a time, but is directed upon the crops of greatest field extent and 
monetary value—wheat, corn, oats, flax, barley, pasturage, hay lands, 
park ways, &c. The possible cost of the process far exceeds that of any 
other type of spraying yet undertaken. 
For this reason alone the author thinks that this work of great agri- 
cultural import should not be left to the slow process of development by 
trial, or to the energetic but wild propaganda of chemical and spraying 
machine companies. Mistakes which may involve the yield of great wheat 
areas are too costly. Exact investigations, chemical, physical, and 
physiological, involving the effects of the various sprays upon the biology 
of the weeds and the crop plants should be undertaken, so that experi- 
menters may be able to give quite explicit explanations of the results 
