ON THE ORIGIN OF LIFE. 



219 



vitality by living matter, conversely the rate of change is 

 checked as the temperature is lowered. As Macallum has 

 put it : " Thus in the case of vital processes which have been 

 investigated, a fall of 10° C. reduces the speed of reaction 

 to 2/5, and, therefore, the rate of reaction responsible for the 

 ultimate loss of vitality would proceed at —220° C. (the 

 temperature of intra- stellar space) at one-thousand-millionth 

 of the rate which obtains at 10° C. ; so that a journey of 

 three thousand million years in space would be no more 

 injurious in effect than one day's exposure to a spring tempera- 

 ture and sunlight on this planet." In the passage of living 

 protoplasm through space, in which the temperature is known 

 to be so low, the amount of drying which it would undergo 

 would be comparatively slight — a most important matter, as 

 extreme desiccation is incompatible with continued vitality. 

 Eoux's* observations on the action of light on the anthrax 

 bacillus make it clear that sunlight, which in the presence of 

 oxygen exerts such a profound influence on the vitality of this 

 micro-organism, is apparently harmless when acting in a 

 vacuum such as that met with beyond the atmosphere that 

 surrounds our globe. 



It is evident that the Panspermic theory of the origin of life 

 explains nothing, even if life was first met with in some other 

 planet than our own. Even there life must have had its origin, 

 and in all probability must have developed progressively from 

 lower and less specific forms to those endowed with much 

 higher attributes ; and as it is impossible for us to prove that 

 life did not originate primarily either here or in another world 

 than ours, the enormous difficulties by which this hypothesis is 

 surrounded are only too obvious. Even the difficulties con- 

 cerning the origin of matter, of its passage through its various 

 phases, afford us little help in our consideration of the origin 

 of life, beyond this, that the same power that moulded the 

 universe must necessarily have endowed some of that matter 

 with the power of housing life." With all this, is it not well 

 that constant controversy should go on between the chemico- 

 physicist and the biologist ? that the physicist should claim 

 that some comparatively highly developed matter endowed 

 with life must have passed from some planet to our own, 

 though it would be difficult to maintain that both animal and 

 plant life can have been developed from such comparatively 

 highly specialized organisms ? the biologist maintaining that 



* Ann. de Vlnst. Pasteur, Paris, 1887, t. T, p. 445. 



