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Of “the unequal action of earlier inheritance” and of the 
“elimination of dissimilar stages” I cannot give any satisfac- 
tory proof from Man’s ontogeny;* but I shall refer to these 
later when I treat of Man’s future. Of “the modification of 
earlier inheritance,” however, the human infant furnishes 
excellent examples. Although able to support the weight of 
its body by the arms directly after birth, it is unable to do the 
same with its legs; yet this want of strength cannot have been 
shewn by itsadult ancestors. My theory supposes that this want 
of strength is, to a certain extent, adaptive—that since the young 
of Man or of monkey has not had to get upon its legs in order 
to suck the mother, strength of leg is not an absolute necessity 
of existence, and it has therefore been temporarily lost by 
disuse. At the same time the material which would have been 
employed to supply this strength is more advantageously and 
economically used elsewhere. If it were an absolute necessity 
that the baby should walk, it would be able to do so directly it 
is born, like calves and lambs.t 
It may be objected that if the loss of leg-power is an 
instance of “ modification of earlier inheritance,” why has not 
the strength of arm been lost also since the human infant does 
*Embryology would furnish proofs. Among Ammonites the proofs are 
numerous, and the reader is referred to my Monograph, published by the 
Palzontographical Society, 1886-1892, et seq. 
+ Kittens, puppies, and young pigs are very awkward in their movements, and 
quite unable to escape from any foe ; these facts may be regarded as instances of 
modification of earlier inheritance. There has been no necessity for them to be 
nimble, as their parents are able to protect them, These animals, too, suck the 
mother when she is lying down, so that they have not even any stimulus to urge 
them to exertion. It would probably be found as a universal law that the young 
of preying animals are ungainly ; while the young of those preyed upon and who 
save themselves by flight are very nimble—like a foal to whom flight is a 
necessity of salvation—unless the mother has some means of carrying, protecting, 
or hiding her young. The same law applies to birds hatched in nests on trees, 
etc,, and to birds (partridges, fowls, etc.) hatched on the ground. The former are 
helpless, unfeathered, and require to be fed, the latter are downy, able to run 
about, and to feed themselves. That the young of dogs, cats, etc., are unable to 
see for some days after birth is again an illustration of the law of modification. 
It arises from these animals having aboriginally been born in caves. 
