THK FRUIT AND ITS ENVELOPES. 



99 



accidentally to come in contact with the plant 

 in tlieir soarcli after food. The hooks or hairs 

 with whicli one part or other of the fructifica- 

 tion is often furnislicd, serving as the medium 

 of attachment, and the seed being tluis carried 

 about witli the animal till it is again detached 

 by some accidental cause, and at last committed 

 to the soil. This is exemplified in tlie case of 

 bidcns and mysotis, in wliich the hooks or 

 prickles are attached to the seed itself; or in tlie 

 case oi galiitm aparini, and others, in whicli they 

 are attached to the pericai'p, or in the case of 

 the thistle anl burdock, in whicli 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 tlie pulpy pericarp, and 

 then drop the stem into the soil. 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 

 hoard 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 squiiTel 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 Ae 

 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 coranthiis 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 of /iAyiofacca decandria, the berries 

 of whicli 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 liave been a little 

 dust collected by way of soil, or where a natural 

 graft may have Ijeen 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 dcgiee of heat without any injury. Spal- 

 lanzani mentions some seeds that germinated 

 after having been boiled 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 transfers to his native soil seeds 

 indigenous to the most distant regions, but sows 

 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 liriodcndron tulipifertim, 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, l)y 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 pknts of the ckiss syn- 

 genesia ; the down 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 tlirough 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 wind 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, witli a membranous 

 wing, which, when they separate from the plant, 

 the wind immediately lays hold oiF and drives 

 before it. 



A further means adopted by nature for the 

 dispersion of the seeds of vegetables, is that of 

 the ini-trumentality of streams, rivers, and cui^ 



