Weismannism up to date (1893). 145 



opinion, should the matter be freed from any such 

 doubt. The question — if there be a question — is one 

 of great interest from a merely physiological point 

 of view, while in relation to the fundamental 

 problems of heredity its importance is immense. 

 Surely, then, any competent botanist who disputes 

 the facts ought to test them by way of experiment. 



But, be this as it may, I must call prominent 

 attention to the following very remarkable words 

 wherewith Weismann concludes the passage above 

 quoted. For he there says, that even supposing there 

 were no doubt as to the facts or their interpretation, 

 "the chief difficulty" which they would oppose to 

 the theory of germ-plasm would be, " that we are 

 here concerned with the influence of the germ-plasm 

 of the sperm-cell on a tissue of another plant which 

 only constitutes a part of this plant." In other words, 

 Weismann now freely entertains the possibility of a 

 direct action of germ plasm on the somatic tissues, 

 even though these belong to another individual ! 

 Thus he now concedes the only point for the 

 establishment of which I adduced the phenomena 

 of xenia, in Chapter III : the whole of one side 

 of that " reciprocal action between the sphere of 

 germinal-substance and the sphere of body-sub- 

 stance/' which I contended for on pp. 76-85, is now 

 conceded ; and although it is the less important 

 side, its surrender goes far to weaken the doctrine 

 of a perpetual isolation of germinal-substance to 

 a "sphere" of its own. If we suppose that the 

 germinal substance of one organism may thus 

 directly act upon the somatic tissues of another, 

 and that changed conditions of life are able to 



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