SOME NOTES ON THE HISTORY AND SIGNIFICANCE 

 OF THE THEORY OF SPONTANEOUS GENERATION. 



By H. STANLEY REDGROVE, B.Sc. (Lond.), F.C.S. 



A belief in the spontaneous generation of such 

 forms of life as mice, maggots, lice, and other 

 vermin out of dirt and decayed organic matter 

 was at one time universally held, and was explicitly 

 taught by Aristotle (see the fifth book of his " History 

 of Animals"). The first work of importance to 

 throw doubt on this theory was done in 1668, when 

 the Italian Redi showed that no maggots were bred 

 in meat, if flies were prevented from laying their 

 eggs on it. In 1683, however, A. van Leeuwenhoek 

 discovered, by the aid of the microscrope, those 

 forms of life, invisible to the naked sight, that are 

 known as "bacteria." This discovery seemed to give 

 considerable support to the doctrine of spontaneous 

 generation, or abiogenesis (as it is now generally 

 called), it being found that, hosvever carefully bodies 

 of organic origin were screened from contami- 

 nation by outside sources, bacteria invariably made 

 their appearance in them. In the middle of the nine- 

 teenth century, however, Pasteur found that if the 

 bodies were first sterilised by heat and prevented 

 from coming in contact with any air other than that 

 which had also been sterilised, no bacteria were 

 developed : milk, for example, he found would 

 keep good for any period in these circumstances. 

 Pasteur's results are accepted by practically all 

 modern biologists and bacteriologists. Professor 

 Charlton Bastian,* however, has more recently 

 carried out numerous experiments with results 

 apparently altogether opposed to those of Pasteur. 

 Indeed, he states that he has obtained growths 

 of bacteria and torulae in inorganic saline solutions 

 containing sodium silicate or colloidal silica (prepara- 

 tions of mineral origin) which had been completely 



sterilised by heat and preserved in hermetically 

 sealed tubes. It is evident that abiogenesis must 

 have taken place at some period of the world's 

 history, for certainly no life could have existed on 

 the earth when it was in a molten condition ; and if 

 one argues (as has been done) that life was first 

 conveyed to this earth by meteorites from other 

 planets, apart from the intrinsic difficulties of this 

 theory, it merely transfers the problem of the origin 

 of life to another planet without in any way simplify- 

 ing it. Given the right conditions, therefore, there 

 seems no valid reason why spontaneous genera- 

 tion should not take place now ; though it is, perhaps, 

 difficult to understand how organised forms of life, 

 such as bacteria, could be immediately produced 

 from inorganic matter; but, as Professor Bastian 

 indicates, the production of the bacteria and torulae 

 in his experiments may have been preceded by the 

 formation of ultra-microscopic specks of unorganised 

 life. Another question that may be asked in 

 connection with these experiments arises out of the 

 fact that protoplasm, which is the material basis of 

 all forms of life, contains carbon as one of its 

 essential elements. Must we assume that a trans- 

 mutation of the elements occurred in Professor 

 Bastian's experiments ? Or is it possible for silicon 

 to take the place of carbon in protoplasm ? However, 

 Professor Bastian's results have not met with general 

 acceptation. It is a pity that his experiments are 

 not repeated by other competent biologists ; some 

 degree of "certainty in the matter might then be 

 obtainable. 



In 1905 Mr. Butler Burke thought he had 

 succeeded in obtaining living " cultures " by the 



;,; In Professor Bastian's experiment very dilute solutions of sodium silicate containing either (i) a few drops of liquor 

 ferri pernitratis (ferric nitrate solution) or else (ii) a very small quantity of ammonium phosphate and phosphoric acid 

 were placed in sterilised glass tubes and hermetically sealed. They were then heated to temperatures varying from 115° C. to 

 145° C, and afterwards exposed to diffused sunlight. After several months they were opened, and the sediment formed 

 by the chemical reaction between the salts when the solutions were heated was examined microscopically. Microphotographs 

 (X 700) of various examples of organisms either observed in the sediment or cultivated therefrom are shown in Figures 

 325-330, which are reproduced on page 292 from " The Origin of Life : being an Account of Experiments with certain super- 

 heated saline Solutions in hermetically sealed Vessels " (Watts, 1911, 3s. 6d. net), by kind permission of Professor Bastian. 

 These figures are as follows : — 



Figure 325. Solution (ii). Heated to 130° C. for 10". Mass of Torulae (" Yeasts "). 

 Figure 326. Solution (ii). Heated to 135° C. for 5". Group of vacuolated Torulae. 

 Figure 327. Solution (ii). Heated to 135° C. for 5". Bacteria. 



Figure 328. Bacteria cultivated from tube shown in Figure 327 as found on ninth day. 



Figure 329. Solution (ii). Heated to 130° C. Mass of Torulae with four Bacteria. Cultivated (ninth day). 

 Figure 330 (from the Second Edition of "The Origin of Life"). Solution (i.). Heated to 100° C. for 20" on 

 three successive days. Mould of Streptothrix type. (X 300). 

 In the case of the experiments, the results of which are shown in Figures 327-329, Graham's pure colloidal silica was 

 used in place of sodium silicate. It was found necessary to use freshly prepared silica or silicate solution. 



It is interesting to know that in control experiments, in which the tubes were opened within a day or two of sealing, 

 no organisms were observed. 



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