ORIGIN OF SEX. i 25 
but the deductions which they have both arrived at, viz.: that the 
begetting of female offspring is a higher role on the part of the 
mother than the es of males, — that is, requires a more 
as a consequence, females are 
more highly Kai than Me are diametrically opposed to 
my own conclusions, as may be seen in this and in the other 
papers referred to. 
The use of the word “vigor” is scarcely scientific ; it has only a 
practical, conventional meaning, and should be studiously avoided 
by scientific biologists, as it is almost useless by way of compar- 
ison. Development is the proper physiological expression, and 
indicates the degree of evolution or maturity of the various organs 
of the animal or plant, and we can readily compare the different 
stages and degrees of development exhibited in each organ. Mr. 
Meehan studiously avoids the use of this last named word, and 
would, I am persuaded, alter his deductions if he should weigh its 
full meaning, and apply it in his comparisons. He cannot, how- 
ever, be too highly praised for his excellent series of observations 
already alluded to. 
ith a view of showing the fallacy of the use of this word vigor, 
I may state that Dr. Gouverneur Emerson of Philadelphia, several 
years ago, discovered that ‘‘the extensive prevalence of every 
severe zymotic epidemic, or endemic disease ; every occurrence, in 
fact, which exerts, either directly or indirectly, a decided, depress- 
ing effect upon a community, will be indicated in the record of 
births by a conspicuous reduction in the proportion of males.” * 
He bases this opinion upon the careful study of the statistics of 
births in Philadelphia during the prevalence of cholera in the year 
1833; also for Paris 1832. In the first named city, the per- 
centage of excess of male births for the decade from 1830 to 1840 
was 6°29, while “the diminution of male conceptions, during the 
cholera, was at the rate of 17 per cent.” The number of concep- 
tions during the months in which cholera prevailed was 1826 
males and 1851 females, or 98-64 males to 100 females. In Paris, 
in 1832, the year cholera prevailed there, the excess of male concep- 
tions was reduced from the usual average of 6 per cent. to 384 per 
cent. From this we see that a ‘‘lessened vigor,” so to speak, is ac- 
companied by an increase in the proportion of female births; so 
*C. perati let ining the Proportions of the Sexes at Birth. American 
Journal of the Medical Sciences, July, 1848, pp. 78-85. 
