88 
TRANSACTIONS OF THE TEXAS ACADEMY OF SCIENCE. 
As the holders of the Lamarckian theory base their views almost en¬ 
tirely on transmitted tail mutilations, Weissman (Essays on Heredity), to 
settle this question, experimented on 901 white mice which were the di¬ 
rect descendants of seven females and five males. Of these 901 young, 
produced from five generations of mutilated parents, in no single instance 
was there an example of an abnormal tail. Of course even a larger num¬ 
ber of experiments like the foregoing prove nothing definitely. It would 
be necessary to carry them to infinity before one could say with certainty 
that a mutilation could not be transmitted. 
This law of transmission of mutilations would entail the existence of a 
mechanism of a wondrous nature; a mechanism so complex that we are 
fain to imagine that nature, who in her methods is usually simplicity 
itself, does not foster it. Each alteration of the body of the parent 
would (under such a law) produce a change in the germ; this change 
would consist, not alone in structural differences, but would be entirely 
functional, causing, say at the 1000th cell generation, an increased or 
decreased growth of cells; this increased or decreased growth in the 
offspring being at a spot corresponding precisely to the overgrowth or 
deficiency in the parent. Now, although it is impossible to prove the 
absolute non-existence of such laws, it is excessively difficult to imagine 
how they work; nor should we expect the results to be as rare as they 
are. Nature's laws are not made to be useless, and to become manifest 
by caprice. They act invariably and continually. If such a law exist, 
how is it that Jews, among whom mutilation of the prepuce has been 
practiced from time immemorial, are not oftener born without this ap¬ 
pendage ? How is it that certain species of sheep, whose tails have been 
habitually mutilated for centuries, so very rarely bear lambs without 
tails or with rudimentary tails ? How is it that fingerless, armless, and 
legless children are not a more common result of paternal accidents in 
our manufacturing districts. 
In conclusion, I consider that this doctrine is not only not proven, but 
stands on no foundation whatever. 
Works referred to: Edinb. Obstetrical Transactions, volumes XVI, 
XVII. J. W. Ballantyne on Maternal Impressions. 
Keating’s Encyclopaedia on Diseases of Children. Article by Dabney 
on Maternal Impressions. 
Ib. Article by Hirst on Monstrosities. 
Dareste. Comptes Rendus, 1873. 
Weissman on Heredity, volume I. 
W. P. Ball. “Are the Effects of Use and Disuse Inherited ?” Page 40. 
