22 
SEED DISPERSAL. 
although it may seem from their structure and place of 
growth that they were made especially to be transported 
by the wind or by some animal. As has been seen in 
examples previously mentioned, one portion of a plant is 
transported in one way, and another portion by one or 
two other methods. 
13. Seeds and fruits as boats and rafts. — An excellent 
place in which to begin investigating this part of the 
subject is to pay a visit to the flats of a creek or river 
late in autumn or in the spring, after the water has 
retired to its narrow channel, and examine piece after 
piece of the rubbish that has been lodged here and there 
against a knoll or some willows, a patch of rushes or dead 
grass. We are studying the different modes by which 
plants travel. In the driftwood may be found dry fruits 
of the bladder nut, brown and light, an inch and a half 
in diameter. See how tough they are ; they seem to be 
perfectly tight, and even if one happens to have a hole 
punched in its side, there are probably two cells that are 
still tight, for there are three in all. Within are a few 
seeds, hard and smooth. Why are they so hard ? Will 
it not be difficult for such seeds to get moist enough and 
soft enough to enable them to germinate ? The hard 
coats enable the seeds to remain uninjured for a long 
time in the water, in case one or two cells of the papery 
pods are broken open; and after the tough pod has 
decayed and the seeds have sunken to the moist earth 
among the sticks and dead leaves, they can have all the 
