58 INHERITANCE. Chap. XIV. 



individuals of the same species, though treated in the same 

 manner. In this latter case we see that the power of trans- 

 mission is a quality which is merely individual in its attach- 

 ment. As with single characters, so it is with the several 

 concurrent slight differences which distinguish sub-varieties 

 or races ; for of these, some can be propagated almost as truly 

 as species, whilst others cannot be relied on. The same rule 

 holds good with plants, when propagated by bulbs, offsets, 

 &c, which in one sense still form parts of the same individual, 

 for some varieties retain or inherit through successive bud- 

 generations their character far more truly than others. 



Some characters not proper to the parent-species have cer- 

 tainly been inherited from an extremely remote epoch, and 

 may therefore be considered as firmly fixed. But it is doubt- 

 ful whether length of inheritance in itself gives fixedness of 

 character; though the chances are obviously in favour of any 

 character which has long been transmitted true or unaltered 

 still being transmitted true as long as the conditions of life 

 remain the same. We know that many species, after having 

 retained the same character for countless ages, whilst living 

 under their natural conditions, when domesticated have varied 

 in the most diversified manner, that is, have failed to transmit 

 their original form ; so that no character appears to be 

 absolutely fixed. We can sometimes account for the failure 

 of inheritance by the conditions of life being opposed to the 

 development of certain characters ; and still oftener, as with 

 plants cultivated by grafts and buds, by the conditions 

 causing new and slight modifications incessantly to appear. 

 In this latter case it is not that inheritance wholly fails, but 

 that new characters are continually superadded. In some 

 few cases, in which both parents are similarly characterised, 

 inheritance seems to gain so much force by the combined 

 action of the two parents, that it counteracts its own power, 

 and a new modification is the result. 



In many cases the failure of the parents to transmit their 

 likeness is due to the breed having been at some former period 

 crossed; and the child takes after his grandparent or more 

 remote ancestor of foreign blood. In other ca^es, in which 

 the brei d has not been crossed, but some ancient character 



