82 THE HUMAN SIDE OF PLANTS 
nut, which live near the water’s edge, and their bal- 
loons are likely to be lost at sea unless some special 
provision is made to save the children in case the 
balloon falls into the water. To this end they have 
made their three gas compartments, each of which 
carries a tiny sailor, safely guarded in an air-tight 
room; and, if by chance the bladdernut grows tired 
of sailing in the air, it may easily light in the water, 
and glide along as smoothly as a water-fowl or a 
man-made hydroplane. 
The children of the linden travel by means of a 
kite-like appendage, which may be used as a life- 
preserver in case the seed falls into the water. The 
narrow-leafed dock, another plant which grows 
near the water, carries a life-preserver attached to 
its seeds. If for any reason the seeds become sep- 
arated from their preservers, they immediately sink 
beneath the water and are lost. 
Many of the grasses and sedges travel by means 
of boats, canoes, and rafts. In the genus Carez, 
the fruit grows in a tiny canoe; and many the craft 
that silently lands its happy passenger in a place of 
safety! In the arrowhead, the cat-tail flag, butter- 
cups, and cinquefoil, there is always some form of 
sail, boat, canoe, or raft, by which the seeds may 
be saved from shipwreck. These life-preservers 
are usually in the form of woody or paper-like ap- 
