258 THE BEGINNINGS OF LIFE. 



animal in which they were found. And, similarly, he 

 believed that the grubs which are to be met with 

 in the galls of plants, are produced by a modification 

 of the living substance of the plant these galls being, 

 in fact, as he thought, organs destined to produce such 

 animals '. In 1745, Needham, who was shortly after- 

 wards elected a Fellow of the Royal Society of Lon- 

 don, came forward with much additional evidence in 

 favour of the doctrine of c spontaneous generation/ and 

 affirmed that, if the mere putrefaction of meat could 

 not of itself engender insects, as Redi had shewn, it 

 could at least give origin to myriads of microscopic 

 animalcules. Four years after the publication of Need- 

 ham's researches, the great naturalist Bufrbn expounded 

 his views 2 concerning 'organic molecules, 5 and the uni- 

 versal origination of the lowest forms of animal life, 

 by a process answering to what was termed c spon- 

 taneous generation/ He said : c There are, perhaps, 



1 'Esperienze intorno alia Generazione degl' Insetti,' p. 129. Redi 

 was therefore a partial believer in the doctrine which we now name 

 Heterogenesis. According to this doctrine, as taught by Burdach and 

 others, strange living things might be generated from the matter of 

 pre-existing living beings, both during their life and after their death. 

 In the opinion of Redi, however, such a process could only take place 

 whilst the parent organism was living (Loc. cit. p. 14). It will after- 

 wards be more fully seen that this is quite an unimportant limitation, 

 because it is one of a purely arbitrary nature, based upon the imperfect 

 knowledge of the time. We now know that the constituent elemental 

 parts of one of the higher organisms may continue to live long after the 

 organism as a whole is dead. 



3 These will be referred to more fully in a subsequent chapter. 



