142 THE NATURE-STUDY OF PLANTS 
to the day. The Meadow Cranesbill, however, whose 
flowers are often more than an inch in diameter, 
took on the average one week longer for each of the 
six that I marked at various times for observation. 
One knows quite certainly when the fruit is ripe, not 
only by the opening of the calyx, but also by the 
colour of the knob, which on maturity loses its green 
and turns brown, but it does not follow that the seed 
is thrown at once or even soon ; on the contrary, that 
depends upon the state of the weather, which must 
be fine and dry. I watched one of the fruits of this 
species daily for a whole week of rainy weather. The 
first-instance dispersal differs from that of the Herb 
Robert and agrees with the Cut-leaved Cranesbill’s, 
which I will describe presently. After the ripening 
of the seed, the knob when sufficiently dry breaks away 
from the base of the bill but not from the spring, 
and moves through an angle of ninety degrees, 
placing itself at right angles to the bill instead of in 
the same straight line. I looked at this particular 
fruit sometimes several times-a day, and what I saw 
was curious. The spring is quite distinctly hygro- 
scopic even a long time after the seed has been shot, 
and there was something rather pathetic in seeing 
the knob sticking out ready for the throw, and then, 
when the rain came down and soused it, moving back 
again to its old position. It went on doing this 
throughout the week, and it was not until the eighth 
day that I found that the seeds had at last been 
ejected. 
In this genus a comparatively large amount of 
difference is to be found in the seeds and in their 
first-instance dispersal, although the mechanism is 
the same throughout. 
