LIFE 349 



other which, without greater inference, brings under a 

 single formula our perceptual experience of both the 

 living and the lifeless. 



S 9. — The Spontaneous Generation of Life, or A biogenesis 



Such a formula is that of the spontaneous generation 

 of life. In the first place, this formula involves the con- 

 ception of forms of protoplasm anterior to those with 

 which we are at present acquainted, but it does not sup- 

 pose these like forms to have existed in unlike conditions. 

 It postulates that if we were to go backwards the organic 

 would have disappeared into the inorganic before we 

 reached the azoic age. After the azoic age the physical 

 conditions must be conceived as such that the various 

 chemical compounds were evolved which ultimately cul- 

 minated in the first protoplasmic unit.^ But if this be so, 

 it may be asked : Why cannot we find this sequence of 

 sense-impressions in our present experience, why cannot 

 we repeat the spontaneous generation of life in our 

 laboratories ? The reply probably lies in the statement 

 that we seek to reverse a process which is irreversible 

 (p. 346). In five or ten minutes we convert living into 

 lifeless substance, but there is no reason for asserting that 

 the reverse process can be gone through even in the life- 

 time of a man. On the contrary, it probably took millions 

 of years, with complex and varying conditions of tempera- 

 ture, to pass from the chemical substance of life to that 

 complex structure which may have been the first stage of 

 organic being. Let us for a moment consider that there is 

 possibly as long an evolution from the chemical substance 



1 Lankester (Article "Protozoa"), remarking on the steps which brought 

 the earliest type of protoplasm into existence, writes: — "A conceivable state 

 of things is that a vast amount of albuminoids and other such compounds had 

 been brought into existence by those processes which culminated in the 

 development of the first protoplasm, and it seems therefore likely enough 

 that the first protoplasm fed upon these antecedent steps in its own evolution 

 just as animals feed on organic compounds at the present day, more especially 

 as the large creeping plasmodia of some Mycetozoa feed on vegetable refuse." 

 These words suffice to indicate the long stages of development that jirobably 

 lie behind protoplasm as we know it. 



