1870.] BRITISH ASSOCIATION. 323 



against the charge of impugniug the authority of the Scriptures 

 (Redi, I. c. p. 45, Fsperienze, p. 120) ; for his adversaries de- 

 chired that the generation of bees from the carcase of a dead lion 

 is affirmed, in the Book of Judges, to have been the origin of the 

 famous riddle with which Samson perplexed the Philistines : 



Out of the eater came forth meat, 



And out of the strong came forth sweetness. 



Against all odds, however, Redi, strong with the strength of 

 demonstrable fact, did splendid battle for Biogenesis; but it is 

 remarkable that he held the doctrine in a sense which, if he had 

 lived in these times, would have infalHbly caused him to be 

 classed among the defenders of '^ spontaneous generation." 

 *' Omne vivum ex vivo," " no life without antecedent life," 

 aphoristically sums up Kedi's doctrine ; but he went no further. 

 It is most remarkable evidence of the philosophic caution and 

 impartiality of his mind, that, although he had speculatively 

 anticipated the manner in which grubs really are deposited in 

 fruits and in the galls of plants, he deliberately admits that the 

 evidence is insufficient to bear him out ; and he therefore prefers 

 the supposition that they are generated by a modification of the 

 liviog substance of the plants themselves. Indeed, he regards 

 these vegetable growths as organs, by means of which the plant 

 gives rise to an animal, and looks upon this production of specific 

 animals as the final cause of the galls and of, at any rate, some 

 fruits. And he proposes to explain the occurrence of parasites 

 within the animal body in the same way. 



It is of great importance to apprehend Bedi's position rightly ; 

 for the lines of thought he laid down for us are those upon which 

 naturalists have been working ever since. Clearly he held 

 Biogenesis as against Abiogenesis ; and I shall immediately 

 proceed, in the first place, to inquire how far subsequent 

 investisration has borne him out in so doinc*. 



But Iledi also thought that there were two modes of Biogenesis. 

 By the one method, which is that of common and ordinary 

 occurrence, the living parent gives rise to offspring which passes 

 through the same cycle of changes as itself — like gives rise to like ; 

 and this has been termed Homogenesis. By the other mode, the 

 living parent was supposed to give rise to offspring which passed 

 through a totally different series of states from those exhibited by 

 the parent, and did not return into the cycle of the parent : this 

 is what ought to be called Heterogenesis, the offspring being 



