V. 
The Recapitulation Theory. 
A REJOINDER. 
F the value of a theory is to be measured by the number and the 
extent of the papers written, and by the amount of work done 
under its inspiration, then the value of the Recapitulation Theory is 
indeed great: but there is always room for the doubt as to whether an 
equalamount of work would not have been done without that inspiration ; 
whether, for instance, Hyatt, Buckman, Jackson, and Beecher would 
not have published researches as great and as brilliant as those re- 
ferred to by Mr. Bather in his article on ‘“‘ The Recapitulation Theory 
in Paleontology” (p. 281), even if they had been inspired by some- 
thing less fantastic than the theory in question. 
In attacking this theory, however, I was fully conscious of the 
enormous amount of work done under its inspiration ; and in attempt- 
ing to destroy the theory, I was fully alive to the possible effect upon 
the work of the future. I look upon the loss of all the ‘“ recapitula- 
tion” literature with perfect equanimity—nay more, I look forward 
with hope for the time when men shall cease to occupy the pages 
of our scientific journals with controversies as to whether ‘“ the 
ancestor” of the vertebrates was an ascidian, polychete, nemertine, 
leech, turbellarian, sea-anemone, sponge, spider, crustacean, Balano- 
glossus, echinoderm or other vecent animal of the embryos of which 
the controversialists happen to have been cutting sections. I do not 
think that if the writings thus briefly catalogued had been written 
without the ‘‘ inspiration” of the Recapitulation Theory, they would 
have been less valuable. The little I do know about the psychology 
of ‘‘dominant ideas” leads me, indeed, to believe that the investi- 
gations would have been carried out, not only more fully, but also 
with far less error of observation. Under the influence of a dominant 
idea, men see what does not exist, and are blind to what lies before 
them ; and what is even worse, what little they do see of the things 
before them is seen distorted. Whether the dominant idea be a true 
idea or a false one, if dominant, it is almost certain to lead to profound 
error. When first the idea of evolution gained a hold over men’s 
minds through the influence of Darwin’s and Wallace’s theory of 
Natural Selection, it suddenly developed into a dominant idea in the 
