168 A HISTORY OF 



unite into a foetus ; beneath the bark of a tree they pullulate into 

 branches ; and, in short, the same particles that first formed the ani- 

 mal in the womb, contribute to increase its growth when brought 

 forth.* 



To this system it has been objected, that it is impossible to conceive 

 organical substances without being organized; and that, if devested of 

 organization themselves, they could never make an organized body, 

 as an infinity of circles could never make a triangle. It has been ob- 

 jected, that it is more difficult to conceive the transformation of these 

 organical particles, than even that of the animal, whose growth we 

 are inquiring after; and this system, therefore, attempts to explain 

 one obscure thing by another still more obscure. 



But an objection, still stronger than these, has been advanced by 

 an ingenious countryman of our own ; who asserts, that these little 

 animals, which thus appear swimming and sporting in almost every 

 fluid we examine with a microscope, are not real living particles, but 

 some of the more opaque parts of the fluid, that are thus increased 

 in size, and seem to have a much greater motion than they have in 

 reality. For the motion being magnified with the object, the smallest 

 degree of it will seem very considerable ; and a being almost at rest 

 may, by these means, be apparently put into violent action. Thus, 

 for instance, if we look upon the sails of a windmill moving at a dis- 

 tance, they appear to go very slow; but, if we approach them, and 

 thus magnify their bulk to our eye, they go round with great rapidity. 

 A microscope, in the same manner, serves to bring our eye close to 

 the object, and thus to enlarge it; and not only increase the magni- 

 tude of its parts, but of its motion. Hence therefore, it would fol- 

 ow, that these organical particles that are said to constitute the bulk 

 of living nature, are but mere optical illusions ; and the system found- 

 ed on them must, like them, be illusive. 



These, and many other objections, have been made to this system; 

 which, instead of enlightening the mind, serve only to show, that too 

 close a pursuit of nature very often leads to uncertainty. Happily, 

 however, for mankind, the most intricate inquiries are generally the 

 most useless. Instead, therefore, of balancing accounts between the 

 sexes, and attempting to ascertain to which the business of generation 

 most properly belongs, it will be more instructive, as well as amusing, 

 to begin with animal nature, from its earliest retirements, and eva- 

 nescent outlines, and pursue the incipient creature through all its 

 changes in the womb, till it arrives into open day. 



The usual distinction of animals, with respect to their manner of 

 generation, has been into the oviparous and viviparous kinds; or, in 

 other words, into those that bring forth an egg, which is afterwards 

 hatched into life, and those that bring forth their young alive and per- 

 fect. In one of these two ways all animals were supposed to have 

 been produced, and all other kinds of generation were supposed ima- 

 ginary or erroneous. But later discoveries have taught us to be more 

 cautious in making general conclusions, and have even induced many 

 to doubt whether animal life may not be produced merely fion 1 pucre- 

 fictiou.i 



Mr. Buffon. t Bonet. Consid. p. 100. 



