

INAUGURAL ADDRESS. 15 
The general ines upon which such experiments would be 
made may be indicated by the questions -— 
Would the young of our Doris inherit or develope the 
peculiar colouring if placed in different surroundings? 
Would they develope a protective colour if placed in such 
circumstances that the action of natural selection would 
be prevented as far as possible by the elimination of 
competition? And would a mimetic resemblance to their 
surroundings be produced much more rapidly if they were 
placed under circumstances of severe competition? I 
fancy the last two questions would be answered in the 
affirmative, and thus indicate that while natural selection 
is the more powerful influence, the environment has also 
some direct effect. 
If, however, we agree with Herbert Spencer and some 
other evolutionists that there are other factors besides 
natural selection in evolution, that use and disuse, the 
environment, and physiological selection all play their 
subordinate parts in the modification of species, and that 
acquired characters are handed on by heredity to future 
generations, then we find ourselves at once brought into 
conflict with the latest and most generally approved theory 
of heredity to which I must now direct your attention. 
Many theories have been brought forward to account for 
the well-known fact that like tends to produce like—that 
the characters of the parents and other ancestors are 
handed down to the offspring. ‘Twenty years ago Darwin 
enunciated his theory of ‘‘ Pangenesis,’’ which was that 
“‘Every cell of the animal’s body, so long as it is not too highly 
differentiated, throws off gemmules, which are capable of multiplying 
by fission, and which retain the characteristics of the cells from which 
they arose, and are capable of reproducing them at some future period by 
developing into similar cells. These gemmules are transmitted to the offspring 
by means of the reproductive elements, and may remain dormant in the new 
individual for a time, or even through a number of gererations. When they 
