364 HISTORY OF 



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 produce an egg, which 

 is afterwards hatched into life, and those that 

 bring forth their young alive and perfect. In 

 one of these two ways, all animals were supposed 

 to have been produced, and all other kinds of 

 generation were supposed imaginary or errone- 

 ous. 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 from 

 putrefaction.* 



Indeed, the infinite number of creatures that 

 putrid substances seem to give birth to, and the 

 variety of little insects seen floating in liquors 

 by the microscope, appear to favour this opinion. 

 But, however this may be, the former method of 

 classing animals can now by no means be admit- 

 ted, as we find many animals that are produced 

 neither from the womb, nor from the shell, but 

 merely from cuttings ; so that to multiply life in 

 some creatures, it is sufficient only to multiply 

 the dissection. This being the simplest method 

 of generation, and that in which life seems to re- 

 quire the smallest preparation for its existence, 

 I will begin with it, and so proceed to the two 

 other kinds, from the meanest to the most da* 

 borate. 



* Bonnet, Consid. p. 100. 



