PHYSIOLOGY OF BREEDING. 
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that it first vitalises, or perhaps produces, the inner layer, and 
next the outer one, which you will recollect I have before 
alluded to as giving rise to the internal and external organs 
of the foetus respectively. This supposition is in perfect 
harmony with the physiological fact, that the internal organs 
are formed first, and the external ones subsequently, and 
appears to me to acquire some degree of confirmation from 
it. If my surmise be a correct one, it will be necessary for 
those who uphold the doctrine of a divided and distinct 
action of each parent, to prove that this action and influence 
can be detected in a point so small as to be called a dot, and 
requiring perhaps the aid of a microscope to render it visible. 
If called upon to assign any rule on this difficult question, as 
perhaps you will think only reasonable, after venturing to 
dispute the opinion of such able observers as Dr. Harvey and 
Mr. Orton, I must give it as my opinion that none can be 
laid down as being of universal application, unless it be the 
old one, that “like produces like,” each after his kind. This 
rule is liable to many disturbing influences, and may be 
modified by many causes, often so secret and mysterious, as 
to defy detection, and to perplex even the most acute 
observer; and to the consideration of these I will now 
direct your attention. But from the length to which this 
paper has already extended, I fear I cannot do more than 
enumerate some few of them without giving the details of the 
observations (chiefly made by others) on which the existence 
of these influences are presumed to exist. 
1st. There is the broad fact, so generally observed, not 
only by Mr. Orton, but by almost every one who has paid 
any attention to this subject, namely, that of the superior in- 
fluence of the male animal. This will be conceded, I imagine, 
without adopting Mr. Orton’s theory, that each parent exer- 
cises an arbitrary and definite influence over isolated parts of 
the offspring. I cannot pretend to solve a question which 
has been found so difficult of solution by the ablest physio- 
logists, but perhaps the profound observations in the latter 
part of Dr. Harvey’s pamphlet may indicate an approximation 
to the true explanation of this interesting fact, and to it I must 
refer those who are anxious to pursue the inquiry further. 
2d. Mr. Orton has also described another rule as affecting 
the offspring, “ that the female system imbibes certain 
influences from the male which modify the future progeny 
of other males.” I may remark in passing, that the existence 
of an element so powerful as this in its influence over the 
offspring, affords us strong additional grounds for venturing 
to doubt Mr. Orton’s first and leading position. However 
