86 
TRANSACTIONS OF THE TEXAS ACADEMY OF SCIENCE. 
presumably to improve their appearance. On the other hand the feathers 
are naturally narrower in this situation, and this narrowing extends even 
higher than the habitually denuded part. Is it not natural to assume 
that the feathers were originally narrower; that this proved a sexual 
attraction, which was intensified by habitual mutilation ? 
Dr. Prosper Lucas quotes a long list of inherited injuries, all of which 
are unsatisfactory and bordering on the romantic. I give a few of his 
cases as samples. He says: “ Many girls are born in London with no 
breasts, owing to the injurious effects of corsets worn by their mothers.” 
He quotes the case of a Jew who could see to read through the thick 
covers of a book, and whose son inherited this acuteness of vision. 
A case is quoted by Richter of a soldier who lost his left eye from in¬ 
flammation, and who had two sons, each with the left eye malformed 
(microphthalmic). The explanation of this case is, that the father was 
micropthalmic, and consequently subject to inflammation, and the sons 
inherited this constitutional condition from their father, and not from the 
effects of inflammation. 
Darwin quotes a case which is mentioned by Ball as being the most 
conclusive and convincing. It is that of Brown-Sequard’s epileptic 
“ Guinea pigs,” who were born with the absence of some of the toes, 
owing to their parents having gnawed off their own gangrenous toes 
when anaesthetic after division of the great sciatic nerve. This case, 
however, is imperfectly reported, and it is not claimed that the deficiency 
was on the same side of the body, or exactly analagous in both parent 
and offspring. 
Darwin’s own explanation of this condition is, that during repair of the 
injured part in the parent, all the representative gemmules, which would 
develop or repair or reproduce the injured part, are attracted to the 
diseased surface during the healing process, and are there destroyed. In 
other words, that a something which is needed to bring about the forma¬ 
tion of any particular part in the child is withdrawn from the germ cells 
of the parent, and in consequence a failure of this part to attain adult 
development. “A very pretty and simple process forsooth ! ” 
A new school has lately sprung up in our midst which has revived the 
doctrines taught by Lamarck. It bases its doctrines on certain changes 
which occur in mammalian teeth as the result of mechanical agencies, 
e. g., rubbing and wearing down of the crowns of teeth from habit or 
accident. This process goes on during the life of the parent, and is be¬ 
lieved to produce similar changes in the offspring. If we grant this fact, 
we prove nothing except that the offspring is able to acquire characters 
which the parent was unable to; for the shape of the teeth is predeter¬ 
mined before they burst through the gum, and before they are subjected 
to any mechanical agencies whatever. 
