■ . V- 



90 ON THE GENERAL ANALOGY OF 



or layers ; and some of these animals, like the house-leek and vanoas 

 grasses, by spontaneous separation. In effect, most of the kinds now 

 referred to, whether animals or vegetables, may be regarded less as single 

 individuals than as assemblages or congeries of individuals ; for in most of 

 them every part exists distinctly of every other part, and is often a minia- 

 ture of the general form. The various branches of a tree offer a similar 

 example, and present a striking contrast with the various branches of a 

 perfect animal. In the latter every distinct part contributes to one perfect 

 whole : the arm of a man has no heart, no lungs, no stomach ; but the 

 branch of a tree has a complete system of organs to itself, and is hence 

 capable in many cases of existing by itself, and producing buds, layers, 

 and other kinds of offspring, when separated from the trunk. The dif- 

 ferent parts of the polype are equally independent, and are hence equally 

 capable of a separate increase. It is owing to this principle we are 

 able to graft and bud : and M. Trembley having apphed the same kind of 

 operation to the animals we are now speaking of, found that, by numerous 

 grafls of different kinds upon each other, he was enabled to produce mon- 

 sters as wild and extravagant as the most visionary poet or fabulist ever 

 dreamed of. 



The blood of plants, like that of animals, instead of being simple is 

 compound, and consists of a great multitude of compacter corpuscles, 

 globules for the most part, but not always globules, floating in a looser and 

 almost diaphanous fluid. From this common current of vitality, plants, 

 like animals, secrete a variety of substances of different, and frequently of 

 opposite powers and quahties, — substances nutritive, medicinal, or destruc- 

 tive. And, as in animal hfe, so also in vegetable, it is often observed that 

 the very same tribe, or even individual, that in some of its organs secretes 

 a wholesome ahmenl, in other organs secretes a deadly poison. As the 

 viper pours into the reservoir situated at the bottom ot his hollow tusk a* 

 fluid fatal to other animals, while in the general substance of his body he 

 offers us not only a healthful nutriment, but, in some sort, an antidote for 

 the venom of. his jaw : so the jatropha Manihot^ or Indian cassava, secretes 

 a juice or oil extremely poisonous in its root, while its leaves are regarded 

 as a common esculent in the country, and are eaten like spinach-leaves 

 among ourselves ; though the root, when deprived, by exposure to heat, of 

 this poisonous and volatile oil, is one of the most valuable foods in the 

 world, and gives bread to the natives, and tapioca as an article of com- 

 merce. Its starch is like that of the finest wheat-flour, and combined with 

 potatoes and sugar, yields a very excellent cider and perry, according to 

 the proportions employed. In like manner, while the bark of the cinna- 

 mon tree (laurus Cinnamomum ) is exquisitely fragrant, the smell of the 

 flowers is highly offensive, and by most persons is compared to that of 

 newly-sawn bones, — by St. Pierre to that of human excrement.* So the 

 cascarilla bark and castor oil are obtained from plants poisonous in some 

 part or other. 



The amyris, in one of its species offers the balm-of-Gilead tree ; in 

 another, the gum-elemi tree ; and in a third,! the poison-ash^ that secretes 

 a liquid gum as black as ink. It is from a fourth species of this genus, I 

 will just observe as I pass along, in order the more completely to familiarize 



* Mr. Marsliairs account deliTered to the Royal Society. See Thomson's Annals, Sept. 

 p. 242. 



"f A. toxifere., 



