Human Physiology. 247 



pieces, each piece produces the missing parts, so as to become 

 a perfect animal, as cuttings of a geranium produce geraniums. 



But perhaps the most curious mode of multiplication takes 

 place in some sea-worms. They divide into sections by con- 

 stricting rings, and each section forms for itself head, eyes, &c., 

 at one extremity, and tail at the other, while yet the sections 

 are united; but when all is ready each section sets up its own 

 independent life, and then produces in its body germs of similar 

 worms, by the more usual process just as some vegetables 

 propagate by seeds, as well as by bulbs or tubers. 



These modes of multiplication fission, gemmation, &c., 

 such as I have described are, however, not the rule in nature, 

 but the exception, or variation a ruder method of the exten- 

 sion of life, which is confined to the lower forms of animal 

 existence. As vegetables are generally produced from seeds, 

 animals are generally produced from eggs. There is no good 

 reason, so far as we now know, to believe that there is any 

 spontaneous generation of vegetables or animals that is, that 

 any vegetable or animal ever of itself is formed from matter 

 without a spore or germ which has been produced by a similar 

 organisation. At some time, and in some way, every kind .of 

 living form had its beginning; but no one has seen such begin- 

 ning. Creation is a mystery. Every living thing upon the 

 earth has at some time, somewhere, and somehow been created; 

 but we do not know the when, the where, or the how. Human 

 science reveals to us something of the phenomena of nature 

 nothing of its causes or beginnings. 



As in vegetables we find the beginning of new organisa- 

 tions in the formation by the generative organs of a plant, 

 which are in most cases portions of its flower, of a germ cell in 

 the ovary or female organ, and of a pollen cell by the anther or 

 male organ, which unite to form the living germ, which develops 

 into the perfect plant so in all the higher forms of animal 

 life, in oysters, fishes, insects, birds, beasts, and men, we have 



