CLASSIFICATION OF LIVING TYPES 51 



ignorant, whilst the radiobe has been produced under 

 conditions which are altogether artificial and could 

 not possibly have existed at that remote period when 

 pristine mud might have been a more likely culture 

 medium than the constituents of fish broth or the 

 essence of beef-tea. 



For all that, however, the production is not un- 

 worthy of being admitted into the sacred precincts of 

 biology, for even if it is like a hot-house plant, the 

 product of artificial conditions, whilst the bacillus is 

 the survival of Nature, the fact that it fits in with 

 our idea of vitality is a sufficient reason for not 

 refusing to regard it as a mode of life. 



Granting then, as we feel compelled to do, that 

 these radio-organic forms are living things in the 

 sense in which we use the word, are we, or are we not, 

 entitled to regard the bodies which give rise to them, 

 the radium salt on the one hand and the sterilised 

 bouillon on the other, as living or containing the 

 elements of vitality ? We should reply : the radium 

 yes, but the bouillon no ; at least, so far as we can at 

 present judge. For one exhibits the particular state 

 or mode of motion with which vitality is associated, 

 but the organic colloid does not. Radium, therefore, 

 may be regarded as the seed, if we may put it so, 

 which grows in the bouillon soil. The constituents 

 of protoplasm are in the bouillon, but the vital flux is 

 in the radium. It is an interesting inference, there- 

 fore, that whilst inorganic bodies have been regarded 

 as devoid of life, and organic bodies as the means of 

 it, we are led to the conclusion that the vital principle 



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