i a 
DANDENO: SEED-DISPERSION IN RICINUS COMMUNIS 91 
line with some violence. This acts just as a spring suddenly 
relaxed ; thus the carpel is projected. This splitting is a loculicidal 
dehiscence and the seed, though projected with the carpel, is at 
this time, or soon after, released, but not before. 
Another structural peculiarity is the prickly surface of the car- 
pel, and this might easily act in conjunction with the explosion, 
from the fact that any slight disturbance immediately before the 
carpels were ready to explode, would cause the explosion, and 
these carpels might then attach themselves to such animal as 
might produce the disturbance. This, however, is not taken into 
consideration. 
To ascertain the magnitude of the energy of expulsion it was 
necessary first to determine the actual distance some of the car- 
pellary parts were projected. This was done in-doors by hanging 
the mature fruiting branches in a natural position at a given dis- 
tance, approximately that of the plant, above the horizontal, and 
then measuring the actual range which the carpels were projected. 
The plants in the garden were similarly examined and the results 
did not differ very materially from those obtained in-doors. The 
average distance from the vertical, of those carpels which seemed 
to be projected from the position most favorable of the three car- 
pels, was found to be 3.65 meters, and the average height of the 
cluster was 1.6 meters. Then, since the angle of rising equals the 
angle of falling, the real horizontal range would be 3.65 — 1.6 
= 2.05 meters. Since the angle of projection is 40°, then 22’, 
sin 40° +9.8 = 2.05 meters. .°.v= 3.6 (approx.) meters per 
second, where v is the velocity of projection. Hence the work 
done in projecting a body weighing .4 grams (the weight of one 
carpel with contents) would be 
2 
( 3s ) X 4.9 X .4 = .264 gram-meters per Sec. 
= 000264 kgm. per sec. 
Since there are 3 carpels to one fruit, and 58 (average) fruits on 
one cluster, and 4 (average) clusters on one plant, each plant 
would do, by the sudden “filliping”’ of the carpels, 
3 x 58 x 4 x.000264 + 76 = .0024 horse powers per second. 
And if each plant requires 4 square feet of ground space upon 
which to grow, on one acre there would be 10,890 plants ; there- 
