614 The Outline of Science 



which the pitcher is partly filled is a secretion of the glandular 

 cells of the wall. The inner surface of the rim is set with nectar 

 glands, and below these the wall is made very slippery by a coat- 

 ing of wax. So it comes about that an insect, attracted by the 

 nectar and straying on to this glissade, slips into the fluid and is 

 drowned. During the subsequent slow digestion the body is not 

 attacked by bacteria, for the fluid in the pitcher is antiseptic as 

 well as digestive and so keeps the food fresh. 



Venus Fly-trap 



Most wonderful of all is the Venus fly-trap, a relative of the 

 sundew, growing like it on bogmoss, but found only in the Caro- 

 linas. Its leaves are over an inch long, each with a winged stalk 

 and a rounded blade. On the upper surface of each half of the 

 blade are three prominent bristles ; round the margin is a row of 

 stiff processes. If an insect touches one of the bristles the two 

 halves of the leaves clap together in something less than a second, 

 the marginal processes interlock like the teeth of a rat-trap, and 

 the insect is captured. And then there are many suggestive de- 

 tails, such as Sir John Burdon Sanderson's discovery, that the 

 closing movement of the leaf is accompanied by an electrical. 

 change similar to that associated with the contraction of one of 

 our muscles. Then follows a secretion so abundant that the fluid 

 oozes out from the edges of the trap. Digestion and absorption 

 follow in due course. After a while the leaf reverts to its normal 

 state of expectancy. 



How Plants and Animals Agree 



If we trace an oak-tree back to a sapling, and thence to a 

 seedling, and thence to a seed and an ovule, we come at last to a 

 fertilised egg-cell, which is the beginning of the individual life. 

 In this respect the oak-tree agrees with the squirrel on its 

 branches. Moreover, in both cases the fertilised egg-cell divides 



