PRODUCTION OF FRUIT 131 
linated flowers produce large quantities of pollen; in 
those which have adopted the improved method of 
utilizing insects, the amount of pollen is much less; 
in the highly specialized Orchids, a most successful 
group, the pollen is reduced to two small bundles. 
Once the act of pollination is effected, the duty of 
- the petals and stamens is finished, and they generally 
fade. The sepals often remain, as in the Rose. By 
the growth of the pollen tube from the stigma into 
the ovary, fertilization is effected, and mature seed is 
produced. The fruit—that is, the seed and its cover- 
ings or appendages—offers the most varied forms of 
any of the plant organs—compare Hazel, Strawberry, 
Pea, Apple, Cranesbill, Dandelion; the variety is end- 
less. Many of these forms are connected with the 
means by which seed-dispersal is effected: this subject 
has been touched on in Chapter III. But in numer- 
ous instances we can no more assign a reason for 
their beautiful or fantastic forms than we can account 
for the infinite variety of shape assumed by leaves 
and flowers. 
Summing up, then, what has been sketched in this 
chapter, we must think of our plant as a very com- 
plicated and wonderful machine, of which the terres- 
trial Seed Plant is the highest expression. Water is 
the basis on which its activities are founded—the cur- 
rency in which all business is transacted. The amount 
of water contained in a growing plant is seldom 
realized. Even solid timber, when growing, is half 
wood, half water. A fresh lettuce loses 95 per cent. 
of its weight if the water is driven off by drying. 
Living in an aerial medium which tends to deprive it 
of moisture continually, and which furnishes water 
