30 THE NATURE-STUDY OF PLANTS 
Small as they are we must remember that the 
mouth of a caterpillar, for example, is but a tiny 
one, and a meal of Enchanter’s-nightshade must be to 
him pretty much what salad or cabbage would be to 
us if a few bundles of fine needles, with a sharp point 
at each end, were mixed in. 
Crystals of this kind are called Raphides, from the 
Greek word for a needle, and another common plant 
which has plenty of them is the Cuckoo-pint or Lords 
and Ladies; nevertheless neither of these species 
entirely escapes being eaten, for each of them has 
its dependents in the caterpillar world, which must 
have learnt in some way or other how te get over the 
difficulty, reminding us of those curious people who 
leave nothing of a herring but the head, tail, and 
backbone. 
The Cuckoo-pint has furthermore another pro- 
tection against being eaten off the face of the earth, 
for it is one of the plants that are poisonous, at any rate 
to many creatures. The question of poisons is one 
that cannot be investigated except by the specialist 
Well-known instances are Hemlock, Belladona, Hen- 
bane, and Aconite among many others; but the more 
important point for the reader to grasp, in view of 
the co-operative nature of the Scheme of Creation, is 
the fact that all these and probably all other plants, 
even the most amply protected and poisonous, have 
their dependent or dependents who look to them 
for some, if not for the whole, of their sustenance : 
poisonous or non-poisonous is, in fact, a relative and 
not an absolute term. 
There is, however, one very easily observed 
example of a poisonous secretion which characterizes 
many of our own common plants. Many gardeners 
