Chap. XIV. SUMMARY. 81 



and complex as the eye ; or of so grave a nature as to deserve 

 to be called a monstrosity, or so peculiar as not to occur 

 normally in any member of the same natural class, are all 

 sometimes strongly inherited by man, the lower animals, and 

 plants. In numberless cases it suffices for the inheritance of a 

 peculiarity that one parent alone should be thus characterised. 

 Inequalities in the two sides of the body, though opposed to 

 the law of symmetry, may be transmitted. There is a con- 

 siderable body of evidence showing that even mutilations, and 

 the effects of accidents, especially or perhaps exclusively when 

 followed by disease, are occasionally inherited. There can be 

 no doubt that the evil effects of long-continued exposure in 

 the parent to injurious conditions are sometimes transmitted 

 to the offspring. So it is, as we shall see in a future chapter, 

 with the effects of the use and disuse of parts, and of mental 

 habits. Periodical habits are likewise transmitted, but generally, 

 as it would appear, with little force. 



Hence we are led to look at inheritance as the rule, and 

 non-inheritance as the anomaly. But this power often appears 

 to us m our ignorance to act capriciously, transmitting a cha- 

 racter with inexplicable strength or feebleness. The very 

 same peculiarity, as the weeping habit of trees, silky-feathers, 

 &c, may be inherited either firmly or not at all by different 

 members of the same group, and even by different individuals 

 of the same species, though treated in the same manner. In 

 this latter case we see that the power of transmission is a 

 quality which is merely individual in its attachment. 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 

 iorm parts of the same individual, for some varieties retain or 

 mnerit 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 doubtful whether 

 length of inheritance in itself gives fixedness of character ; though 



VOL. II. & 



G 



