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The Descent of Man

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males; but he suggests that this preponderance<br />

may be due to some unknown difference in the<br />

habits <strong>of</strong> the two sexes. With one <strong>of</strong> the higher<br />

Brazilian crabs, namely a Gelasimus, Fritz Muller<br />

found the males to be more numerous than<br />

the females. According to the large experience<br />

<strong>of</strong> Mr. C. Spence Bate, the reverse seems to be<br />

the case with six common British crabs, the<br />

names <strong>of</strong> which he has given me.<br />

THE PROPORTION OF THE SEXES IN<br />

RELATION TO NATURAL SELECTION.<br />

<strong>The</strong>re is reason to suspect that in some cases<br />

man has by selection indirectly influenced his<br />

own sex-producing powers. Certain women<br />

tend to produce during their whole lives more<br />

children <strong>of</strong> one sex than <strong>of</strong> the other: and the<br />

same holds good <strong>of</strong> many animals, for instance,<br />

cows and horses; thus Mr. Wright <strong>of</strong> Yeldersley<br />

House informs me that one <strong>of</strong> his Arab mares,<br />

though put seven times to different horses, pro-

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