PLANTS THAT ARE CARRIED BY ANIMALS. 79 
them in growing are crowded and starved to death. A 
very small proportion fall on good ground, and succeed in 
becoming fruiting plants. A large plant of purslane pro- 
duces one million two hundred and fifty thousand seeds ; 
a patch of daisy fleabane, three thousand seeds to each 
square inch of space covered by a plant. The genuine 
student will not be satisfied till he has selected several 
different kinds of plants and counted, or estimated, the 
number of seeds produced by each, or the number of seeds 
furnished to the area covered by one or by several plants. 
