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Oct 12 Passiflora gracilis

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Chapt 8

can survive to the full average duration maturity of life; & we have every reason to believe that death fall heavily on the weak & inexperienced young. If then a certain number proportion of the young offspring were to vary at birth or soon afterwards in some manner which at this age was of not the least service to them at this age, the chances of the preservation of such varying young animals would be small. We have good evidence under domestication how soon variations of any kind, if all lost, if not selected. are lost. But variations which occurred at or near maturity, & which were then of immediate of service to either sex, or those which had occurring similar variations which had occurred at an earlier in life of period & had chanced to survive, would probably be preserved. & inherited As this principle has an important bearing on sexual selection, it may be worth while advisable to give an imaginary illustration. We will take the case of a pair of animals, neither very

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Chap 8

An experienced observer remarks*45 (L) that in Scandinavia the broods of the Capercali and Black-cock contain more males than females; and that with the Dal-ripa (a kind of Ptarmigan) more males than females attend the leks or places of courtship; but this latter circumstance is accounted for by some observers by a greater number of hen birds being killed by vermin. From various facts given by White of Selborne, 46*(LL) it seems clear that south of England, the males of the Partridge must be in considerable excess; and I have been assured that this is the case in Scotland. Mr. Weir on enquiring from the dealers who receive at certain seasons large numbers of Ruffs (Machetes pugnax) was told that the males are much the most numerous. This same naturalist has also enquired for me from the bird-catchers, who annually catch alive an astonishing number of various small species for the London market, and he was unhesitatingly answered by an old and trustworthy man, that with the chaffinch the males are in large excess; he thought as high as 4 2 males to 2 1 females, or at least as high as 5 to 3.47*(LLL) The males of the Black-bird, he likewise maintained, were by far the most numerous, whether caught by traps or by netting