ADAPTATIONS OF SEEDS AND FRUITS. 223 



The use of poisonous fruits is an interesting subject for con- 

 sideration. How is a plant benefited by producing them ? 



Mr. Grant Allen suggests with regard to a near relative of our 

 Jack-in-the-pulpit that its brilliant scarlet berries are readily de- 

 tected and eaten by birds ; that such birds are consequently poi- 

 soned, and by decaying provide abundant nourishment for the 

 germinating seeds. He adds that birds can not profit by experi- 

 ence and avoid the berries, as no bird ever lives to tell the tale. 



At first this explanation seems very reasonable, and perhaps 

 it is ; but we have reason for doubting it, for we find that many 

 fruits poisonous to mammals are eaten by birds without the 

 slightest injury. The beautiful apple-like manchineel, which is 

 most virulently poisonous, is eaten by tropical birds with the 

 greatest impunity. 



On the whole it seems very likely that some fruits are fatal to 

 other animals but not to birds, and under all explanations poisons 

 are doubtless a protection, at least, to the fruits which possess 

 them. 



Many fruits have been so highly cultivated by man that they 

 can no longer set their seeds as originally. Our wild red cherry 

 is a convenient morsel for even small birds ; but its highly cul- 

 tured relatives of the garden must submit their flesh to birds who 

 can not eat stones as well. The case of the strawberry is differ- 

 ent, however, for birds can scarcely take a morsel that does not 

 contain numbers of the small, hard "straws," which are really 

 the most essential parts of the plant, for each one incloses a 

 seed. 



In many cases Nature economically develops as little sweet 

 pulp as will serve her purpose. In the wild red cherry, for in- 

 stance, the stone occupies almost the entire fruit, there being only 

 a thin layer of food substance. Often there is none whatever, 

 and instead the fruit attains its ends by simulated attractiveness. 

 The rosary bean temptingly displays its brilliant red seeds, 

 which are in reality of stony hardness. Yet it does not wholly 

 rely upon this artifice, for it is very probable that part of the 

 seeds are scattered by the twisting dehiscence of the tough pod. 



In some instances the deception is really wonderful. Some 

 pods and seeds mimic insects so closely as probably to entice in- 

 sectivorous birds to carry them, at least until the birds find out 

 their mistake. It may be also that this appearance protects them 

 from graminivorous birds. There are pods which curiously re- 

 semble worms and spiders and caterpillars. Our common castor- 

 oil bean bears a superficial likeness to a beetle. Yet there are 

 some most remarkable cases of mimicry where beetles are coun- 

 terfeited in the minutest detail. 



Fruits are also disseminated by mammals as well as birds. 



