_ 1891.] The Origin of the Galapagos Islands. 317 
distribution ; the researches of Joel A. Allen and Dr. Merriam are 
highly instructive in this line. It is also admitted by nearly all 
paleontologists. I have expressed the opinion that “ inheritance ” 
takes place only after a very long repetition of the same stimulus 
on an organism. Why is it not imaginable that under certain 
conditions, when the organization, instead of receiving an endless 
repetition of a stimulus, suddenly receives a single most effective 
stimulus, that thé effects are inherited, and appear for some gen- 
erations? I do not want to be misunderstood; I do not believe 
in the general inheritance of mutilations ; nobody can believe in 
such atheory. But that certain mutilations, under certain con- 
ditions, may ġe inherited, this I think is a possibility which cannot 
be entirely neglected. And we have to consider such cases, 
dark and unexplainable as they appear. Of course, in the origin of 
species, I do not think that this question is of any importance, 
If even certain mutilations in nature weuld become inherited, 
they could not have any influence whatever on the great harmonic 
number of the same species. I do not think that a species has 
ever been developed through inheritance of a mutilation. I think 
we are yet far from understanding the true nature of inheritance. 
` The objection will be made to me that I do not consider the 
sexes at all. To this I may reply that I am not inclined at pres- 
ent to lay so much stress on the effects of the mingling of differ- 
ent germ-plasmas. This mingling doubtless produces slighter or 
greater individual variation, and is certainly one factor of varia- 
tion. But we have to consider that nearly all our researches on 
variation in this respect are based on domesticated ‘organisms, which 
are, of course, under entirely different conditions from those in 
free natyre. I can only think that certain even apparently most 
useful variations, created by the mingling of the germ-plasmas, 
must soon be swallowed up by the governing mass of harmonic 
forms, and are thus generally unable to develop a new branch. 
I consider sexual union more as a stimulative than a formative 
factor. The same causes that produce variation in asexual 
must produce variation in sexual animals. What we 
have to do is to study species and variation in nature; to study 
ir conditions of life, their surroundings; to find out how these 
