THE FRUIT AND ITS ENVELOPKS. 



DD 



accidentally to come In contact with the plant 

 in their search after food. The hooks or hairs 

 with which one part or other of the fructifica- 

 tion is often furnished, serving as the medium 

 of attachment, and the seed being thus carried 

 about with the animal till it is again detached 

 by some accidental cause, and at last committed 

 to the soil. This is exemplified in the case of 

 bidens and mysotis, in which the hooks or 

 prickles are attached to the seed itself ; or in the 

 case of galium aparini, and others, in which they 

 ai-e attached to the pericarp, or in the case of 

 the thistle and burdock, in which they are 

 attached to the general calyx. Many seeds are 

 dispersed by animals in consequence of their 

 pericarps being used as an article of food. This 

 is often the case with the seeds of the drupe, as 

 cherries, sloes, and haws, all which birds often 

 carry away till they meet with some convenient 

 place for devouring the pulpy pericarp, and 

 then drop the stem into the soU. And so also 

 fruit is dispersed that has been hoarded up for 

 the winter, though even with the view of feed- 

 ing on the seed itself, as in the case of nuts 

 collected by squirrels, which hoards are often 

 dispersed by some other animal. Sometimes the 

 hoai-d is deposited in the ground itself, in which 

 case part of it is generally found to take root 

 and spring up into plants. But it has been ob- 

 served that the ground squirrel often deprives 

 the kernel of its germ before it deposits the fruit 

 it collects, which it has been supposed to do 

 from some peculiar instinct, as the means of pre- 

 venting the germination of the seed. It has 

 been suggested, however, that the preference 

 thus given to the embryo arises, perhaps, fi-om 

 its possessing some specific flavour peculiarly 

 agreeable to the animal's taste, and this is, per- 

 haps, the true solution of the question. Crows 

 have been also observed to lay up acorns and 

 other seeds in the holes of fence posts, which 

 being either forgot or accidentally thrust out, fall 

 ultimately into the earth and germinate. 



But sometimes the seed is even taken into the 

 stomach of the animal, and afterwards deposited 

 in the soil, having passed through it unhurt. 

 This .is often the case with the seed of many 

 species of berry, such as the misletoe, which the 

 thrush swallows, and afterwards deposits upon 

 the boughs of such trees as it may happen to 

 alight upon. The seeds of the coranthus Ameri- 

 canus, and other perennial plants, are said to be 

 deposited in like manner on the branches of the 

 cocoloba grandiflora, and other lofty trees ; as 

 also the seeds cAphytolacea decandria, the ben-ies 

 of which are eaten by the robin, thrush, and 

 wild pigeon. And so also the seeds of currants 

 or roans are sometimes deposited after having 

 been swallowed by blackbirds, or other birds, as 

 may be seen by observing a currant bush or 

 young roan tree, growing out of the cleft of an- 



other tree, where the seed has been left, and 

 where there may happen to have been a little 

 dust collected by way of soil, or where a natural 

 graft may have been effected by the insinuation of 

 the radicle into some chink or cleft. It seems 

 indeed surprising that any seeds should be able 

 to resist the heat and digestive action of the 

 stomach of animals; but it is undoubtedly the fact. 

 Some seeds seem even to require it. The seeds 

 of magnolia glauca, which have been brought to 

 this country, are said to have generally refused 

 to vegetate till after undergoing this process, and 

 it is known that some seeds will bear a still 

 greater degiee of heat without any injury. Spal- 

 lanzani mentions some seeds that germinated 

 after having been boUed in water, and Du Hamel 

 gives an account of some others that germinated 

 even after having been exposed to a degree of 

 heat equal to 285° of Fahrenheit. In addition 

 to the instrumentality of animals in the disper- 

 sion of the seed, may be also added the labours 

 of man, who for purposes of utility, or of orna- 

 ment, not only transfos to his native soil seeds 

 indigenous to the most distant regions, but sowb 

 and cultivates them with care. 



The agency of wind, too, is a powerful means 

 of the dispersion of seeds. Some are fitted for 

 this mode of dispersion from their extreme 

 minuteness, such as those of the mosses, lichens, 

 and fungi, which float invisibly in the air, and 

 vegetate wherever they happen to meet with a 

 suitable soil. Others are fitted for it by means 

 of an attached wing, as in the case of the fir tree, 

 and liriodendron tulipiferum, so that the seed, in 

 falling from the cone or capsule, is immediately 

 caught by the wind, and carried to a distance. 

 Others are peculiarly fitted for it, by means of 

 their being furnished with an agrette or down, 

 as in the case of the dandelion, goat's beard, and 

 thistle, as well as most plants of the class syn- 

 genesia ; the dovm of which is so large and 

 light in proportion to the seed it supports, that 

 it is wafted in the most gentle breeze, and is 

 often seen floating through the atmosphere in 

 great abundance at the time the seed is ripe. 

 Others are fitted for this mode of dispersion by 

 means of the structure of their pericarp, which 

 is also wafted along with them, as in the case of 

 staphylea trifolia, the inflated capsule of which 

 seems as if obviously intended thus to aid the 

 dispersion of the contained seed, by its exposing 

 to the vvind a large and distended surface with 

 but little weight. And so also in the case of the 

 maple, elm, and ash, the capsules of which are 

 furnished, like some seeds, with a membranous 

 wing, which, when they separate from the plant, 

 the wind immediately lays hold off' and drives 

 before it. 



A further means adopted by nature for the 

 dispersion of the seeds of vegetables, is that, of 

 the instrumentality of streams, rivers, and cur- 



