SPONTANEOUS GENERATION 



655 



us. The matter is therefore one of historic interest 

 chiefly. As long ago as 1870 Huxley, in his presi- 

 dential address to the British Association, was 

 able to say that it appeared to him, within certain 

 limitations, that the doctrine of Biogenesis, that 

 life proceeds from life only, was victorious along 

 the whole line. These limitations were, he said, 

 that if he could have been a witness of the early 

 stages of the earth's history, when the physical 

 and chemical conditions were different from those 

 that now hold, he would have expected to see the 

 evolution of living protoplasm from non-living 

 matter. As these limitations are still often thought 

 inconsistent, and as by other people the denial of 

 spontaneous generation seems inconsistent with a 

 belief in evolution, it will be well to quote Herbert 

 Spencer's reply to a critic who urged objections on 

 this ground of inconsistency. In his Principles of 

 Biology (vol. i., Appendix, 1868) he says, ' I do not 

 believe in the " spontaneous generation " commonly 

 alleged, and so little have I associated in thought 

 this alleged "spontaneous generation," which I 

 disbelieve, with the generation by evolution, which 

 I do believe, that the repudiation of the one never 

 occurred to me as liable to be mistaken for repudi- 

 ation of the other. That creatures having quite 

 tpecific itructures are evolved in the course ol a few 

 hours, without antecedents calculated to determine 

 their specific forms, is to me incredible. Not only 

 the established truths of Biology, but the estab- 

 lished truths of science in general, negative the 

 supposition that organisms having structures 

 definite enough to identify them as Belonging to 

 known genera and species can be produced in the 

 absence of germs derived from antecedent organ- 

 isms of the same genera and species. If there can 

 suddenly be imposed upon simple protoplasm the 

 organisation which constitutes it a Paramecium I 

 see no reason why animals of greater complexity, 

 or indeed of any complexity, may not be consti- 

 tuted in the same manner. In brief, I do not 

 accept these alleged facts as exemplifying evolu- 

 tion, because they imply something immensely 

 beyond that which evolution, as I understand it, 

 can achieve. In the second place, my disbelief ex- 

 tends not only to the alleged cases of "spontaneous 

 generation," but to every case akin to them. The 

 very conception of spontaneity is wholly incon- 

 gruous with the conception of evolution.' On the 

 other hand he says, 'Granting that the forma- 

 tion of organic matter and the evolution of life in 

 its lowest forms may go on under existing costnical 

 conditions, but believing it more likely that the 

 formation of such matter and such forms took 

 place at a time when the heat of the earth's 

 surface was falling through ranges of temperature 

 at which the higher organic compounds are un- 

 stable, I conceive that the moulding of such organic 

 matter into the simplest types must have com- 

 menced with portions of protoplasm more minute, 

 more indefinite, and more inconstant in their char- 

 acters than the lowest Rhizopods less distinguish- 

 able from a mere fragment of albumen than even 

 the Protogenes of Professor Haeckel. The evolu- 

 tion of specific shapes must, like all other organic 

 evolution, have resulted from the actions and 

 reactions between such incipient types and the 

 environment, and the continual survival of those 

 which happened to have specialities best fitted to 

 the specialities of their environments. To reach 

 by this process the comparatively well-specialised 

 forms of ordinary infusoria must, I conceive, have 

 taken an enormous period of time." Again, 'That 

 organic matter was not produced all at once, but 

 was reached through steps, we are well warranted 

 in believing by the experience of chemists. Organic 

 matters are produced in the laboratory by what 

 we may literally call artificial evolution. Chemists 



find themselves unable to form these complex com- 

 binations directly from their elements, Imt they 

 succeed in forming them indirectly by successive 

 modifications of simpler combinations.' We may 

 say then that it is certain that living organisms, 

 large enough to be visible with the help of a micro- 

 scope and definite enough in form and structure to 

 be classified with other known genera, do not grow 

 at present from non-living matter. But it is not 

 therefore certain that protoplasm of living matter 

 may not be so formed in extremely small quanti- 

 ties, too small to be visible and of simple or no 

 structure, but yet sufficiently complex in composi- 

 tion to serve as food for other and more highly 

 developed animals. Whether this be so or not, 

 Huxley and Spencer and nearly all biologists 

 agree in l>elieving that in past time molecules of 

 simple matter by some series of reactions became 

 aggregated until a matter, sufficiently complex and 

 sufficiently unstable to be called living matter, was 

 formed, whilst there is no evidence that any such 

 generation is taking place at present. 



We will now give a summary of the history of 

 this inquiry, based upon Huxley's presidential 

 address of 1870, and to a less extent upon 

 TymlalFs article in the Nineteenth Century, Janu- 

 ary 1878. Expressions and phrases will be freely 

 quoted from these authors. 



History. It must always have been a matter of 

 common experience that many articles of food are 

 apt to become mouldy and to putrefy if kept too 

 long. Associated with mould and w'ith putrefac- 

 tion are various sorts of low forms of life. The 

 ancient philosophers never doubted that these were 

 generated in the matters in which they made their 

 appearance. Indeed, all men believed this until 

 past the middle of the 17th century. But in 1660- 

 in Italy, in those days the home of learning, Fran- 

 cesco Redi published his Esperienza intorno alia 

 Generazione degV Insetti. He was no theorist, but 

 a careful experimenter. Here, said he, is meat ; 

 if I expose it to the air in hot weather, in a few 

 days it putrefies and swarms with maggots ; but if 

 I protect similar pieces of meat by covering them 

 with fine gauze, then, though they still putrefy, nob 

 a maggot makes its appearance. From this experi- 

 ment it l>ecomes obvious that the maggots are not 

 generated in the meat, but that the cause of their 

 formation is something that is kept away by fine 

 gauze. This something can be easily shown to be 

 Blowflies, for these, attracted by the meat, swarm 

 near it and lay their eggs on the protecting gauze, 

 eggs from which maggots are shortly hatched. 

 Now this is the principle of the whole matter; 

 keep away all living things which might come to 

 the meat and' the meat will not create any living 

 things, will not even putrefy if one kills any living 

 animals or germs of animals that may be in the 

 meat. The protecting gauze must be fine enough, 

 that is all. Kedi of course was accused of contro- 

 verting Scripture, because of the story of the bees 

 which were said to be generated in the carcass of 

 the lion. But his doctrine of Biogenesis flourished 

 for a century. Indeed when, through the develop- 

 ment of the microscope, the numerous provisions 

 for the production of germs were made known, 

 the hypothesis of Abiogenesis, that life could 

 come from what was not living, appeared absurd. 

 Leeuwenhoek (q.v.), 1632-1723, is remarkable as 

 being the first man to demonstrate existence of 

 unicellular organisms. During the 18th century 

 the microscope was greatly improved. The ani- 

 malcules (infusoria) which in a few days will 

 swarm in any infusion of organic matter became 

 visible, and Needham, on theoretical grounds, 

 doubted whether Redi's generalisation, 'no life 

 without antecedent life,' held true for these 

 lowly forms of life. He put his doubts to the 



