ADAPTATIONS IN ANIMALS AND PLANTS 29 



their bodies unaffected. These seeds are favored in their 

 germination by the heat and moisture to which they have been 

 subjected, and perhaps later derive nourishment from the 

 excreta passed with them. The fruits bearing the seeds often 

 possess bright colors as they ripen and are charged with agree- 

 ably tasting juices which render them edible to animals. 

 Some of these fruits are poisonous to some animals, but 

 harmless to others. The bright orange mountain-ash berries are 

 much enjoyed by the common waxwing; the black elderberries 

 are consumed by several species of birds; and Wallace states 

 that there is probably nowhere a brightly colored pulpy fruit 

 which does not serve as a food for some species of bird or 

 mammal. The drupes of the poison ivy are freely devoured 

 by crows and in this way the plant is widely disseminated 

 in our woods. 



While the seeds are often dispersed as above described, it 

 is an interesting fact, as Grant Allen has mentioned, that 

 the fruits of our forest trees are protected during their develop- 

 ment. At this time they are green when on the tree and hardly 

 visible among the foliage, but as they ripen they turn brown and 

 fall to the ground. Such, for instance, are the beech, butter- 

 nuts, chestnuts, and the walnuts. The beechnuts and chestnuts 

 are provided with a prickly coat that protects them to some 

 extent, while the butternuts and walnuts have an acrid, pungent 

 covering before they are ripe. I have seen young red squirrels 

 eat nearly ripe beech and butternuts, biting through and 

 discarding the outer covering. Out of the enormous cjuantities 

 of these nuts that are produced some are doubtless able to 

 propagate and produce young trees. The wild pigeons that 

 formerly ranged over North America in such enormous flocks 

 fed on acorns, which they swallowed whole without bruising, 

 and these were digested and used up in nutriment. Squirrels 

 and gophers are fond of acorns, and these nuts are destroyed 

 by the acorn weevil, yet with all the great number of them 

 consumed, there are enough produced that some of them find 

 favorable places for germination and growth. 



The smaller plants, such as grasses, sedges, composites, and 

 umbelliferas, drop their seeds directly to the ground, and these 

 have obscurely colored capsules and small brown seeds. Plants, 



