a 
TRANSACTIONS OF SECTION D. 769 
teproductive organs will, because of the intervention of conjugation, appear as an 
increase in genetic variability only. How will the matter stand in the case of 
asexual reproduction ? First, with regard to modifications which do not affect the 
reproductive system—they, as in sexual reproduction, will not be transmitted. 
Secondly, as regards modifications which do affect the reproductive organs—they 
will be transmitted, z.c. they will affect the next generation; and the question 
arises, how will they be transmitted? or here we have the opportunity wanting 
in the case of sexual reproduction of studying the transmission of modifications 
of the reproductive system without the complications introduced by the act of 
conjugation. ; 
In considering this matter, it must be remembered that the reproductive 
organs are with regard to external influences exactly as any other organ. They 
can be modified either directly or indirectly, though they are in animals often less 
liable to direct moditication by reason of their internal position! These modifica- 
tions may, as in the case of other organs, be obvious to the eye of the observer, or 
they may be so slight as only to be detected by an alteration of function. Now, 
in the case of the reproductive organs this alteration of function will show itself 
in the individuals of the next generation (if not before) which proceed directly and 
without any complication from the affected tissue. How will these individuals he 
affected P Will they all be affected in the same kind of way, or will they be affected 
in different ways? Finally, will the modification last their lives only, or will it 
continue into subsequent asexually produced generations ? 
Let us endeavour to answer these questions :— 
(1) How will the offspring be affected? That will depend entirely upon how 
the reproductive organ was affected. Will the modification in the offspring have 
any adaptive relation whatever to the external cause? Now here we have a 
capital opportunity, an opportunity not afforded at all by sexual reproduction, of 
examining by experiment and observation the Lamarckian position, My cwn 
opinion is that there will be no relation of an adaptive kind between the external 
cause and the modification of the offspring. For instance, let us imagine, as an 
experiment, that a number of parthenogenetically reproducing organisms are sub- 
mitted to a temperature lower than that at which they are accustomed to live. 
Let us suppose that the cold affects their reproductive organs and produces a modi- 
fication of the offspring. Will the modification be in the direction of enabling 
the offspring to flourish in a lower temperature than the parent? My own opinion, 
as I have said, is that there will probably be no such tendency in the offspring, if 
all possibility of selection be excluded. But that is only an opinion. The question 
is unsettled, and must remain unsettled until it is tested upon asexually reproduc-, 
ing organisms. 
(2) Will they all be affected in the same kind of way? Yes, presumably they 
will. I arrive at this conclusion, not by experiment, but by reasoning from analogy. 
In the case of other organs of the body, the same external cause produces in all 
individuals acted upon, roughly speaking, the same kind of effect, e.g. action of 
sun upon skin, effect of transplanting maize, Porto Santo rabbits, &c. The 
question, however, cannot be settled in this way. It requires an experimental 
answer. 
(3) Will the modification last beyond the life of the individuals produced by 
the affected reproductive organ? I can give no answer to this question. We 
haye no data upon which to form ajudgment. We cannot say whether it is possible 
permanently to modify the constitution of an organism in this way, or whether, 
however strong the cause may be, consistently of course with the non-destruction 
of life, the effects will gradually die away—it may be in one, it may be in two or 
more generations. There are cases known which might assist in settling these 
questions, hut I must leave to another opportunity the task of examining them. 
I refer to such cases as Artemia salina, various cases of bud variation which 
cannot be included under the head of growth variation, 
1 How far the abnormal position of the testes of mammalia may receive its 
explanation in this connection is a question worthy of consideration, 
Pp q J 
1899, 3D 
