SOME PROBLEMS IN EVOLUTION. 
ADDRESS TO SECTION D (ZOOLOGY) BY 
Professor EDWIN S$. GOODRICH, F.R.S., 
PRESIDENT OF ‘TIM SECTION 
Ir was nearly 100 years ago that Charles Darwin began his scientific 
studies in the University of Edinburgh. In this illustrious centre of 
intellectual activity he met various friends keenly interested in natural 
history, and attended the meetings of. scientific societies, and it was 
doubtless. here that. were sown many of the seeds destined to bear such 
glorious fruit many years later. No more fitting subject, I think, 
‘could be found for an address than certain problems relating to his 
. doctrine of evolution. That controversy perpetually rages round it is 
a healthy sign. For we must take care in science lest doctrine should 
pass into dogma, unquestioned and accepted merely on authority. So 
from time to time it is useful to re-examine in the light of new knowledge 
the very foundations on which our theories are laid. 
Perhaps the best way of treating these general subjects is by trying to 
answer some definite questions. For instance, we may ask: ‘ Why 
are some characters inherited and others not?’ By characters we 
mean all those qualities and properties possessed by the organism, and 
by the enumeration of which we describe it: its weight, size, shape, 
colour, its structure, composition and activities. Next, what do we 
mean by ‘inherited’? It is most important, if possible, clearly to 
define this term, since much of the controversy in writings on evolution 
is due to its use by various authors with a very different significance— 
sometimes as mere reappearance, at other times as actual transmission 
or transference from one generation to the next. Now, I propose to use 
the word inheritance merely to signify the reappearance in the offspring 
of a character possessed by the ancestor—a fact which may be observed 
and described, regardless of any theory as to its cause. Our question, 
then, is: ‘ Why do some characters reappear in the offspring and others 
not?’ 
It is sometimes asserted that old-established characters are inherited, 
and that newly-begotten ones are not, or are less constant, in their 
Yeappearance. This statement will not bear critical examination. For, on 
the one hand, it has been conclusively shown by experimental breeding 
that the newest characters may be inherited as constantly as the most 
ancient, provided they are possessed by both parents.‘ While, on the 
other hand, few characters in plants can be older than the green colour due 
to chlorophyll, yet it is sufficient to cut off the light from a germinating 
for the greenness to fail to appear, Again, ever since Devonian 
1 We purposely set aside complications due to hybridisation and Mendelian 
_ Segregation, which do not directly bear on the questions at issue. 
H 2 
