42 
thus, in effect, a pair of jaws and a stomach combined—a pair of 
jaws to snatch, a stomach to digest its food. 
Having now, so to speak, swallowed their fly, the respective 
plants remain closed until the operation of digestion is completed 
—a period of five days in the case of the Sun-dew ; of ten days, or 
double the time, in the case of the Venus Fly-trap. The plant 
then opens again, ready to recommence its operations, and the 
dry shell of the fly, from which the digestible matter has been ex- 
tracted, may be seen adhering to the leaf, like the dry carcase of a 
fly in a spider’s web, after the spider has sucked the juice. 
But it is to be observed that these plants close upon every 
solid object that comes, whether it be good to eat, or whether it 
be not—it may be a fly, or it may be a speck of dust, the plant 
closes upon it just the same. But in the case of its having 
swallowed something not good to eat, the plant opens again; the 
Sun-dew in about seventeen hours, the Fly-trap in about thirty-nine 
hours—again about double the time. It seems evident from this, 
that it is only by attempting to digest what it has swallowed that 
the plant finds whether or not it is good to eat; for you will see 
that the plant of slower digestion, which requires double the time 
to digest its food, requires also double the time to find out whether 
what it has swallowed is fit to eat ; so that it seems clear that it is 
only when the process of digestion is ripe for commencing, tha 
the plant finds out that what it has taken is not capable of being 
digested. When I say that these plants close on everything that 
comes, the statement must be subjected to a certain qualification. 
It must be something that comes, as a fly comes, with a light and 
titillating touch. A speck of dust would do it, but anything 
coming with a stronger impact, would produce no effect. And 
you will at once see how essential this is to the life of the plant. 
If the impact of a drop of rain, for instance, were to cause the 
plant to close, it might be kept closed till it was starved to death. 
The nerves of the plant, then, which set its closing machinery 
in motion, have the property of being stimulated only by a slight 
touch, and not by a heavy one. And this is a property by no 
means confined to this particular plant. Take the common nettle, 
