An Introduction to a Biology 



alive and part of its very being ; the pigments with which 

 the picture is painted are dead and might just as well have 

 been used, and of course have been used, by other species 

 to paint different pictures. Bergson's analogy between the 

 organism and a retort does not appear to me to be a perfect 

 one, because we are apt to gather from it that the distinc- 

 tion to be emphasised is between inside and outside, whereas 

 it is, of course, between essentially vital and not-essentially- 

 vital, or rather not-at-all- vital, in fact dead. And we have 

 just seen that some of the chief non-living constituents are 

 the farthest outside, namely, the pigments to which the 

 term " contents " does not apply at all. 



Let us now re-state conciselv the four main conclusions 

 to which a consideration of M. Bergson's philosophy has 

 led us : — 



1. Time is the essential factor concerned in the fixa- 



tion of the characters of organisms. 



2. Life is perpetually creating the absolutely new ; 



more is got out in the effect than is put in in the 

 cause. 



3. The performances of living things cannot be pre- 



dicted mathematically. 



4. The organism consists of an essentially vital part 



and of non-living constituent parts. 



Now look at the Mendelian principles of Heredity, which 

 are offered to the breeder as an instrument of great value. 



(1) One of the chief claims of the Mendelian is that 

 his theory gives, for the first time, a coherent scientific 

 explanation of the fixation of characters. Fixity of a par- 

 ticular character, according to the Mendelian, is due to 

 the fact that the organism which bears that character was 

 the result of the union of two germ-cells, both of which 

 contained the factor for that character. Li Mendelian terms, 

 the organism was homozygous for that character. In- 



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