Inheritance of Acquired Characters 239 



tions of certain sheep-dogs is due to such inheritance." The 

 answer that Darwin gives is that the gemmules themselves, 

 that were once derived from the part, are still present in 

 other parts of the body, and it is from these that the organs 

 in the next generation may be derived. But Darwin fails to 

 point out that, if this were the case, it must also be true for 

 those cases in which an organ is no longer used. Its decrease 

 in size in successive generations cannot be due to its disuse, 

 for the rest of the body would supply the necessary gemmules 

 to keep it at its full state of development. Thus, in trying to 

 meet an obvious objection to his hypothesis, Darwin brings for- 

 ward a new view that is fatal to another part of his hypothesis. 



The following cases, also given by Darwin, are admitted by 

 him to be inexplicable on his hypothesis : " With respect to 

 variations due to reversion, there is a similar difference be- 

 tween plants propagated from buds and seeds. Many varie- 

 ties can be propagated securely by buds, but generally or 

 invariably revert to their parent forms by seed. So, also, 

 hybridized plants can be multiplied to any extent by buds, 

 but are continually liable to reversion by seed, — that is, to 

 the loss of their hybrid or intermediate character. I can 

 offer no satisfactory explanation of these facts. Plants with 

 variegated leaves, phloxes with striped flowers, barberries 

 with seedless fruit, can all be securely propagated by buds 

 taken from the stem or branches ; but buds from the roots of 

 these plants almost invariably lose their character and revert 

 to their former condition. This latter fact is also inexplica- 

 ble, unless buds developed from the roots are as distinct from 

 those on the stem, as is one bud on the stem from another, 

 and we know that these latter behave like independent or- 

 ganisms." As Darwin here states, these facts appear to be 

 directly contradictory to his hypothesis, and he makes no 

 effort to account for them. 



The entire question of the possibility of the inheritance of 

 acquired characters is itself at present far from being on a 



