mutilations and the like a% 



reaction is a mere scar. Why should one expect the offspring to 

 have a shorter tail because its parent has been curtailed ? Might 

 one not as reasonably expect a longer tail ? No one has ever 

 observed that the descendants of much-pruned fruit-trees or 

 decorative shrubs are any the smaller in consequence. The 

 length of the hair in offspring is not known to be affected by the 

 frequent cropping, clipping, or shearing of their parents. In 

 fact, the structural results of most mutilations are not modifi- 

 cations in the usual sense. 



(5) But there are cases in which the removal of a part has 

 deeply saturating effects. Thus the removal of a thyroid 

 gland may have an influence on many parts of the body. In 

 such cases, therefore, the possibility of the germ-cells being in- 

 fluenced is more conceivable. But, unless the change in the 

 offspring — supposing that there is some change — corresponds to 

 the direct change wrought upon the parent, we have not to deal 

 with modification-inheritance of the first degree, which is the 

 only question under dispute. 



(6) Since the structural change due to a mutilation is not on 

 the same plane as the ordinary modifications which occur in 

 nature, we do not expect useful results from further mutilation 

 experiments. We may refer, however, to the suggestion made 

 by Dr. J. W. Ballantyne,* that in this connection, as with other 

 modification experiments, investigators err by beginning at too 

 late a stage, after the organism is firmly set. It may be that ex- 

 periments on early stages would yield more positive results. It 

 may be that the germ-cells in their early generations are more 

 reachable by, or sensitive to, somatic influences. 



Illustrations. — In our brief discussion of this well-worn subject, 

 we shall for convenience distinguish three categories : (a) amputa- 

 tions, such as docking the tail ; (b) wounds, such as the rupture 

 of the hymen ; (c) deformations, such as the compression of the 



* "Discussion on Heredity in Disease," Scottish Med. and Surg. Journal, 

 vi. (1900), p. 312, 



