714 
HEREDITARY INFLUENCE. 
five toes of the silk cock, but, strange enough, while three of 
them have downy plumage, the other has feathers/’ 
Besides this very remarkable perturbing influence we must 
also consider the phenomenon of atavism, or ancestral influ- 
ence, in which the child manifests striking resemblance to 
the grandfather or grandmother, and not to the father or 
mother. The fact is familiar enough to dispense with our 
citing examples. How is it to be explained? It is to be 
explained on the supposition that the qualities were trans- 
mitted from the grandfather to the father, in whom they were 
masked by the presence of some antagonistic or controlling 
influence, and thence transmitted to the son, in whom, the 
antagonistic influence being withdrawn, they manifested 
themselves. As Longet remarks, “ S’il n’y a pas heritage 
des caracteres paternels il y a done au moins ajptitude a en 
heriter, disposition a les reproduire, et toujours cette trans- 
mission de cette aptitude a de nouveaux descendants, chez 
lesquels ces memes caracteres se manifesteront tot ou tard.”* 
Mr. Smith, let us say, has a remarkable aptitude for music; 
but the influence of Mrs. Smith is such that their children, 
inheriting her imperfect ear, manifest no musical talent what- 
ever. These children, however, have inherited the disposi- 
tion of their father in spite of its non-manifestation ; and if, 
when they transmit what in them is latent, the influence of 
their wives is favorable, the grandchildren may turn out to 
be musically gifted. In the same way consumption or 
insanity seems to lie dormant for a generation, and in the 
next flashes out with the same fury as of old. Atavism is 
thus a phenomenon always to be borne in mind as one of the 
many complications of the complex problem. Very remark- 
able is the atavism exhibited by some of the lower animals, 
who bring forth young so utterly unlike themselves as to 
have been long mistaken for different species ; while these 
young in their turn bring forth animals exactly like their 
ancestors. Here the children of one generation always re- 
semble their grandfathers and grandmothers, and never their 
fathers arid mothers.f 
A third cause of complication is one which we propose to 
call “ the potency of race or individual.” Both father and 
mother transmit their organizations, but they do so in un- 
equal degrees: the more potent predominates ; just as if you 
mix brandy with equal amounts of water, soda water, and 
ginger beer, the taste of the brandy will predominate more 
* ‘Traite de Physiologie,’ ii, 133. 
+ See Steenstrup on ‘ The Alternation of Generations ; ’ and Owen on 
‘ Parthenogenesis.’ 
