Nature has a number of quite effective ways of preventing thefts of this kind, one of the most 
common ways being to provide the plant stem with bristly hairs, forming a very difficult barrier for 
any crawling insect to overcome; others have a tuft of hair at the very entrance to the honey cells 
which bar the way for unwelcome guests, but readily allow the bee to insert its tongue; still others 
are protected by recurved leaves or by sticky stems, or as in the toadflax by a two-lipped flower, 
which will open under the weight of a bumblebee, but is effectively closed to any lighter insect. 
The seeds, having been set, are enclosed in a capsule composed of the closed and dried sepals, 
the petals having fallen off; in a pod as in the peas and beans; or in fruit, as inside an apple, which 
is formed by the base of the flower enlarging about the seeds with the calyx remaining at the top of 
the ripened fruit, or in the strawberry, where the seeds are on the outside of the berry and the 
calyx at the bottom of the fruit. It is plain that should these seeds simply fall to the ground, 
plants of a single species would soon become so crowded in a small area that the earth could not 
support them. Consequently various means are furnished different plants for the dispersion of 
their seeds. A great number, like the thistles, milkweeds and dandelions, have plume-like para¬ 
chutes provided for each seed, so they can float away on the breeze to new fields; those that have 
their seeds embedded in fruit are entrusted to birds to be carried where fate wills it; others, like 
beggar-ticks, burdock, etc., have spines to attach themselves to the clothing of people or to the 
coats of animals that brush against them. 
As certain insects prey upon plants or rob them of their nectar, so certain plants prey upon 
insects, literally eating them or absorbing them into their system. Best known among these is the 
pitcher plants, a swamp species, whose leaves are pitcher-like and with a hood or awning over the 
top to keep out the rain; these leaves are half filled with a sweet fluid that attracts insects, makes 
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