APPENDIX D 211 



deductively, it must follow, as, indeed, may easily be proved 

 inductively, that changes in a germ-cell tend to be reproduced in 

 its descendant germ-cells, for which reason the organisms which 

 arise from them tend also to reproduce the inborn variations of 

 the parent organism. 



An acquired character may be defined as one which arises in 

 the organism owing to changes produced by the action of the 

 environment, not on the germ-cell, but on the somatic cells 

 derived from it. If acquired modifications are transmissible, then 

 changes in the somatic cells must tend so to modify the germ- 

 cells associated with them that, as a consequence, the organisms 

 they proliferate into tend to reproduce, as inborn characters, the 

 particular modifications which were acquired by the parent 

 organism. 



I daresay that the above definitions may be objected to by 

 some of my readers, but I have hopes that, on consideration of 

 what follows, the majority will assent to them as indicating pretty 

 correctly what we really mean by the terms " inborn " and 

 "acquired." I do not here propose to discuss the question as to 

 whether acquired modifications are transmissible ; I have done it 

 at length elsewhere, and my present object is rather to differentiate 

 accurately between the acquired and the congenital, and to 

 ascertain the parts played by them respectively in the organic 

 world. I may, in passing, however, notice one or two points 

 which have been frequent sources of confusion, and the considera- 

 tion of which may help to bring the meaning I intend my 

 definitions to bear clearly before the mind. 



It has often been maintained by Neo-Lamarckians that 

 important modifications in the soma (e.g. the effects of disease) 

 must affect the associated germ-cells, and that, therefore, acquired 

 modifications must, to some extent, be transmissible. They 

 miss the point at issue. It is not denied that changes in the 

 germ's environment (i.e. in the body of the parent) may result in 

 modifications in the organism into which the germ subsequently 

 proliferates, but it is strenuously denied that acquired modifica- 

 tions in the parent tend specially so to modify the germ as to 



