ON ORGANIZED BODIES, &c. 



of their course, have to oppose the attraction of gravitation instead of being 

 able to take advantage of it. It is in the present day, however, a well- 

 known fact, and has been sufficiently ascertained by the late Dr. Parry of 

 Bath, and on the Continent by Professor Dollinger, that the contractile 

 power of the muscular fibres is not called into action even by the arteries 

 in the course of the ordinary circulation of the blood, since, as we shall 

 have occasion to observe, no increase of size or change of bulk of any 

 kind takes place in arteries either in the contraction or dilatation of the 

 heart's ventricles in a state of health, unless where they are pressed upon 

 by the finger or some other cause of resistance. 



In what part of a plant the vital principle chiefly exists, or to what quar- 

 ter it retires during the winter, we know not ; but we are just as ignorant 

 in respect to animal life. In both it operates towards every point ; it.con- 

 sists in the whole, and resides in the whole ; and its proof of existence is 

 drawn from its exercising almost every one of its functions afid effecting its 

 combinations in direct opposition to the laws of chemical affinity, which 

 would otherwise as much control it as they control the mineral world, and 

 which constantly assume an authority as soon as ever the vegetable is 

 dead. Hence the plant thrives and increases in its bulk ; puts forth annu^ 

 ally a new progeny of buds, and becomes clothed with a beautifijl foHage 

 of lungs (every leaf being a distinct lung in itself*) for the respiration of 

 the rising brood ; and with a harmonious circle of action, that can never 

 be too much admired, furnishes a perpetual supply of nutriment in every 

 diversified form, for the growth and perfection of animal life ; while it re- 

 ceives in rich abundance, from the waste and diminution, and even decom- 

 position of the same, the means of new births, new buds, and new harvests. 



In fine, every thing is formed for every thing ; and subsists by the kind 

 intercourse of giving and receiving benefits. The electric fire that so 

 alarms us by its thunder, and by the awful effects of its flash, purifies the 

 stagnant atmosphere above us ; and fuses, when it rushes beneath us, a 

 thousand mineral veins into metals of incalculable utility. New islands 

 are perpetually rising from the unfathomable gulfs of the ocean, and enlarg- 

 ing the boundaries of organized life ; sometimes thrown up, all of a sud- 

 den, by the dread agency of volcanoes, and sometimes reared impercepti- 

 bly by the busy efforts of corals and madrapores. Liverworts and mosses 

 first cover the bare and rugged surface, when not a vegetable of any other 

 kind is capable of subsisting there. They flourish, bear fruit, and decay, 

 and the mould they produce forms an appropriate bed for higher orders of 

 plant-seeds, which are floating on the wings of the breeze, or swimming on 

 the billows of the deep. Birds next alight on the new-formed rock, and 

 sow, with interest, the seeds of the berries, or the eggs of the worms and in- 

 sects on which they have fed, and which pass through them without in- 

 jury ; and an occasional swell of the sea floats into the rising island a mixt 

 mass of sand, shells, drifted sea-weed, skins of the casuarina, and shells of 

 the cocoa-nut. Thus the vegetable mould becomes enriched with animal 

 materials ; and the whole surface is progressively covered with herbage, 

 shaded by forests of cocoa and other trees, and rendered a proper habita- 

 tion for man and the domestic animals that attend upon him. 



The tide that makes a desolating inroad on one side of a coast, throws 

 op vast masses of sand on the opposite : the lygeum, or sea-matweed, that 



* On the leafing of trees, there is a curious and valuable paper in the Swedish AmoenitateE 

 Academicae? vol. iii, art, 46. by H. Sarck, 1753, entitled V«niatio Arborum. 



