16 LIFE: ITS NATUEE, OKIGIN AND MAINTENANCE 



ledge as to the mode of origin of life which is unfortunately true but 

 that we never can acquire such knowledge which it is to be hoped is not 

 true.* Knowing what we know, and believing what we believe, as to the 

 part played by evolution in the development of terrestrial matter, we are, 

 I think (without denying the possibility of the existence of life in other 

 parts of the universe t), justified in regarding these cosmic theories as 

 inherently improbable at least in comparison with the solution of the 

 problem which the evolutionary hypothesis offers. J 



I assume that the majority of my audience have at least a general 

 idea of the scope of this hypothesis, the general acceptance of which has 



within the last sixty years altered the whole aspect 



The evolutionary hy- not only of biology, but of every other branch of 



pothesis as applied J . . J 



to the origin of life, natural science, including astronomy, geology, physics, 



and chemistry. To those who have not this know- 

 ledge I would recommend the perusal of a little book by Professor 

 Judd, entitled ' The Coming of Evolution,' which has recently appeared 

 as one of the Cambridge manuals. I know of no similar book in 

 which the subject is as clearly and succinctly treated. Although the 

 author nowhere expresses the opinion that the actual origin of life 

 on the earth has arisen by evolution from non-living matter, it is 

 impossible to read either this or any similar exposition in which 

 the essential unity of the evolutionary process is insisted upon 

 without concluding that the origin of life must have been due to the 

 same process, this process being, without exception, continuous, and 

 admitting of no gap at any part of its course. Looking therefore at the 

 evolution of living matter by the light which is shed upon it from the 

 study of the evolution of matter in general, we are led to regard it as 

 having been produced, not by a sudden alteration, whether exerted by 

 natural or supernatural agency, but by a gradual process of change from 

 material which was lifeless, through material on the borderland between 



* ' The history of science shows how dangerous it is to brush aside mysteries 

 i.e., unsolved problems and to interpose the barrier placarded " eternal no thorough- 

 fare." ' R. Meldola, Herbert Spencer Lecture, 1910. 



t Some authorities, such as Errera, contend, with much probability, that the 

 conditions in interstellar space are such that life, as we understand it, could not 

 possibly exist there. 



J As Verworn points out, such theories would equally apply to the origin of any 

 other chemical combination, whether inorganic or organic, which is met with on our 

 globe, so that they lead directly to absurd conclusions. Allgemcine Physiologic, 1911. 



As Meldola insists, this general acceptance was in the first instance largely due 

 to the writings of Herbert Spencer : ' We are now prepared for evolution in every 

 domain. ... As in the case of most great generalisations, thought had been moving 

 in this direction for many years. . . . Lamarck and Buffon had suggested a definite 

 mechanism of organic development, Kant and Laplace a principle of celestial evolu- 

 tion, while Lyell had placed geology upon an evolutionary basis. The principle of 

 continuity was beginning to be recognised in physical science. ... It was Spencer 

 who brought these independent lines of thought to a focus, and who was the first to 

 make any systematic attempt to show that the law of development expressed in its 

 widest and most abstract form was universally followed throughout cosmical processes, 

 inorganic, organic, and super-organic.' Op. cit., p. 14. 



