Form and Color in Nature. 251 



came crowded, no field was left for the new-comers ; not 

 even standing room was to be had, and any variation which 

 made dispersion probable tended to perpetuate itself. Thus 

 many seeds gradually developed plumes or membranous 

 wings, and so, borne on the wind, were carried to " fresh 

 woods and pastures new." Others developed curious spines 

 or hooks or viscid exudations, by which they caught in the 

 hair or wool of animals, and were carried away. Others 

 again accumulated edible substance, by which birds or mam- 

 mals might be lured, and many of these, to draw attention 

 to them among the surrounding leaves, put on contrasting 

 colors of yellow, or red, or purple, or blue an enormous va- 

 riety. And all sorts of devices were used to make the fruits 

 attractive. Sometimes, as in the apple, it was the calyx 

 which gathered nourishment, increased and softened and 

 enveloped the seeds which were inclosed within a scaly 

 sack ; sometimes, as in the fig, a large number of blossoms 

 and seed-vessels were inclosed within a common receptacle, 

 which likewise developed. Sometimes, as in the raspberry, 

 a multitude of seeds, each surrounded by its own fleshy 

 pulp, were clustered upon the receptacle. Again, as in the 

 strawberry, the receptacle itself became fleshy and bore the 

 seeds in depressions upon the surface the fig, as it were, 

 turned inside out. And to protect the seeds from destruc- 

 tion by the animals which swallowed them, they were often 

 very minute, and were usually covered with a hard, scaly 

 shell. Then again, as in the peach, the seed has become 

 large, but the shell is of great density and difficult to break. 

 Then, as in many of the nuts, the kernel is first protected 

 by a hard shell, and this in turn is covered with a bitter 

 rind. In the case of the cocoanut, the tree bears its fruit 

 far away from all enemies excepting the monkeys, at the 

 summit of a tall, slender stem, and then protects it with a 

 hard shell, and covers this again with a thick fibrous mat- 

 ting, which prevents it from splitting when it falls to the 

 ground. You can readily see how minute variations in all 

 these directions, by providing increased protection to the 

 seeds, and therefore insuring germination, would tend to 

 increase, and become more and more distinct and peculiar. 



The birds have had most to do with the smaller fruits, the 

 berries, etc., and mammals with the larger ones. 



Fruits of many kinds have tended to accumulate sugar 

 and other nutritious substances, sometimes in the seed 

 itself, often in its protective covering, and this of course has 



