204 Inheritance of Acquired Characters 
to which is directly due the fashioning of the adaptation 
even to the smallest details.” 1° 
But Weismann could very lightly deny to these very 
perfect structural formations any value as even indirect 
proof of the principle of inheritance. From his point 
of view he needs only to object that since they are useful 
to the species they can then be very easily explained by 
natural selection alone, and no refutation would be 
possible. 
Inborn characters have the tendency to become like 
those which the ancestors acquired by functional adapta- 
tion, and this coincidence speaks also in favor of the 
hypothesis of the inheritance of acquired characters. But 
against this also Weismann would have no lack of words 
and apparent arguments. 
Functional adaptation, he could reply, renders the 
species more capable of resistance. The greater the 
individual disposition to this adaptation the more 
rapidly the adaptation will proceed. Consequently those 
individuals upon which this disposition is especially 
impressed will survive, and above all those individuals 
in which this adaptation is already existent potentially 
in their germ plasm. Thus the coincidence in question _ 
could be explained without requiring the adoption of 
the inheritance of acquired characters. 
In this way one would arrive at the conclusion that 
all characters susceptible of being produced by the innu- 
merable functional adaptations must for that very reason 
be always useful to the species, so that they can be fixed 
even when they happen to be actually produced by fortu- 
itous inborn variation. We shall not consider this further 
**°Roux: Der Kampf der Teile im Organismus. P. 3o. 
