Sir

I have now to state more fully in reply to your letter of 5^th. inst. in which in behalf of Mr Darwin you propose certain questions relative to the comparative numbers of the sexes born from any flock of sheep or herd of Cattle, in any one or more years, also whether there is noticeable any excess of mortality in either sex over the other, at birth or afterwards (independently of Castration) that Cattle or sheep are not bred at Castle Forbes to any extent.¹ I have, however, laid these subjects before certain gentlemen on whose veracity and accuracy thorough reliance may be placed, and from them have derived the following information.

I. Anthony Cruickshank Esq. Sittyton, Aberdeenshire in a letter to me dated “7^th. Mo. 20^th. 1869 For a period over 20 years we have slightly had an excess of Bull over Heifer Calves, with the exception of last year, when we had 60 Bulls + 68 Heifers, & as far as we know, are alive at present: in 1867 60 Bulls & 54 Heifers and about this proportion of sexes in former years as near as we can arrive at. We don’t know the proportion of deaths at calving or dead at birth, no memo being kept of these. Our deaths on the whole range from 3 to 7 p. cent at and after birth”

II. Robert Bruce Esq. Newton, Kinloss, Morayshire, gives as follows

III. David Gibb Esq.² Bridge of Dye, Kincardineshire, states “I have 5 bull & 11 heifer calves this year, and last year I had equal numbers, and the year before that 9 bull and 8 heifer calves. As to sheep I have generally more females than males. Exact numbers I cannot state but say 30 annually. If you wait a month I shall give you the exact numbers for this year”

I may add that Mr Cruickshank is the largest holder of Cattle with whom I am acquainted, and perhaps the most extensive breeder of these in the north of Scotland. Mr. Gibb has for many years had upwards of 4000 sheep.

Trusting that these statistics may be useful as far as they go I submit them. I may mention that there is an impression among cattle breeders in Aberdeenshire that as a cow is served early or late, at the time she comes into season, there is greater probability of the one sex than the other, and that in the case of poultry the age of the male serves in some measure to determine the preponderance of the respective numbers of the sexes.

I am, | Sir, | Yours most obdt. servant | James Rait