VEGETABLE AND ANIMAL LIFE. 95 



; 



in our last lecture, submitted to your attention a brief outline of the structure 

 of plants, I shall now proceed to point out a few of these general resem- 

 blances, and shall endeavour to select those which are either most curious or 

 most prominent.* 



Plants, then, like animals, are produced by ordinary generation; and 

 though we meet with various instances of production by the generation of 

 buds and bulbs, or of slips and offsets, the parallelism, instead of being 

 hereby diminished, is only drawn the closer ; for we meet with just as many 

 instances of the same varieties of propagation among animals. Ttius the 

 hydra, or polype, as it is more generally called, the asterias, and several spe- 

 cies of the leech, as the himdo, viridis, for example, are uniformly propagated 

 by lateral sections, or pullulating slips or offsets;! while almost every genus 

 of zoophytic worms is only capable of increase by buds, bulbs, or layers ; and 

 some of these animals, like the houseleek and various grasses, by spontane- 

 ous separation. In effect, most of the kinds now referred to, whether ani- 

 mals or vegetables, may be regarded less as single individuals than as assem- 

 blages or congeries of individuals ; for in most of them every part exists dis- 

 tinctly of every other part, and is often a miniature 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 or- 

 gans 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 different parts of the polype are equally independent, and 

 are hence equally capable of a separate increase. It is owing to this princi- 

 ple that we are able to graft and bud : and M. Trembly, having applied the 

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

 numerous grafts of different kinds upon each other, he was enabled to pro- 

 duce monsters 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 com- 

 pound, 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, likp animals, 

 secrete a variety of substances of different, and frequently of opposite powers 

 and qualities, — substances nutritive, medicinal, or destru(;tive. And, as in 

 animal life, 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 aliment, 

 in other organs secretes a deadly poison. As the viper pours into the reser- 

 voir situated at the bottom of 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 jaws : so the 

 Jatropha manihot^ or Indian cassava, secretes a juice or oil extremely poison- 

 ous 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 commerce. 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 cinnamon tree (laurus cinnamomuin) is exquisitely fragrant, the 

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

 that of ncwly-sawn bones,— by St. Pierre to that of human excrement. j So 



• Consult also Mr. Knight'f) article, Phil. Trans. 1810, part ii. p. 179—181. 



r Thus Aristotle, upon a subject which is generally supposed to be of modern discovery, "Sla-KCf> ydp rd 

 <l)VTit KM TavTu (scilicet) cvTo^a ^unpovncva (UviiTai ^?>- For, like plants, such insects also maintain life 

 after slips or cuttinj^s." — Hist. Anim. lib. iv. ch. 8. 



See a variety of other curious instances in the author's translation of Lucretius, note to b. ii. ver. 880. 



% Mr. Marshall's account delivered to the Royal Society. See Thomson's Annals, Sept. p. 242. 



