OR EQUIVOCAL GENERATION. 369 



themselves by division or by shoots ; but it must be remembered 

 that the greater part of them may be considered as an assem- 

 blage of beings, — as for instance, in a tcenia, in which each 

 succeeding joint, as they are commonly called, is an exact 

 repetition of the preceding, so that if a part of it is broken off, 

 it is as equally organized as the parent ; none of its functions 

 are deficient ; the only difference is, that it has not so many of 

 its descendants attached to it. The shoots of a polypus, 

 animal flower, &c. are equally perfect animals with the parent, 

 capable of receiving nutriment, or even of propagating, before 

 they separate. This mode of generation is only found in those 

 animals whose organization is the most simple and the most 

 equally distributed through the whole body, so that when the 

 parts separate, each possesses a sufficient organization for its 

 future life. It is never found in the higher organized beings ; 

 still, even where it is found, a parent of the same type is required. 

 There is no doubt but that a particular state of the secretions is 

 more favourable for the nutriment and increase of all parasites, 

 whether external or internal ; just as every plant requires a 

 particular soil, or every other organized being a particular 

 kind of nourishment. 



We know of no instance of equivocal generation in any of 

 the lower grades of animal or vegetable life that are open to 

 continued observation : it is only assumed in the case of those 

 beings whose minute size evades the sight unless aided by the 

 most delicate instruments, or whose habitation is so obscure, 

 that in order to be seen, their lives must pay the price of it : 

 and therefore in neither case can they be observed, but at 

 detached periods of their lives. In those whose reproduction 

 has been observed, it varies very much : nearly, if not quite all 

 the different modes that have been observed, have been found 

 among the Infusoria or Intestina ; we cannot tell whence the 

 germs come in the infusions ; but that is no reason that we 

 should declare they spring from nothing. In the various vege- 

 table infusions which produce animalcules, what a dilemma 

 spontaneous generation leaves us in ! we must either admit 

 that the vital principle of the animalcule springs from absolute 

 nothing, or else that vegetable matter, whether living or dead, 

 can produce animal life ; a which I hope shows the absurdity of 



a The difficulties attending spontaneous generation, induced one celebrated 

 natural historian of the last century to deny life to the infusoria and spermatic 



