144 SCIENCE PROGRESS. 



Now let us take two sentences quoted by Sir Edward 

 Fry from Weismann in the discussion already referred to : 

 " By the term acquired characters I understand those 

 which do not exist originally in the germ as tendencies ". l 

 And again : "An organism cannot acquire anything unless 

 it already possesses the predisposition to acquire it". 2 It 

 follows, from the first of these quotations, that there are, in 

 Weismann's view, characters which do exist originally in 

 the germ as tendencies ; and, seeing these are not acquired 

 characters, they must have been inherited from the original 

 germ of all organic life. This then is obviously the history 

 of all non-acquired characters ; and it must be noted that 

 the definition quoted above seems to show that Weismann's 

 idea of a predisposition or tendency agrees with my own, 

 viz., that it is a character, property, or function, of the 

 organism in question. Next, let us endeavour to trace the 

 history of an "acquired" character. Its acquisition re- 

 quires, according to Weismann, a "predisposition" in the 

 organism acquiring it ; if by a predisposition is meant any- 

 thing definite, that something must be regarded as a pro- 

 perty or function ; and that function, according to Huxley, 

 is an expression of the molecular structure of the organism. 

 If this view be accepted, it excludes the idea that the func- 

 tion is the direct result merely of external forces acting on 

 the organism ; and only two alternative interpretations 

 seem to me possible : either this predisposition or tendency 

 is inherited ; or it has sprung up spontaneously, and inde- 

 pendently either of the "molecular forces exerted by the 

 structures," or of the direct action of external forces. The 

 latter is of course the hypothesis of a vital plastic force 

 originating independently of matter, a theory which will 

 hardly be accepted by modern biologists of the Darwinian 

 or post- Darwinian school. But, unless we accept this 

 hypothesis, then — if the arguments I have used have any 

 validity — the essential distinction which some have at- 

 tempted to draw between "acquired" and "non-acquired" 



1 Das Keimplasma, p. 514. 



2 Essays on Heredity, 2nd Engl, ed., vol. i., p. 171. 



