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Darwin Correspondence Project

From James Oliver to George Cupples   3 July 1869


3d July 1869


I have been from home for the last three weeks on account of my health, and only came home this afternoon, when I found yours of the 29 ult. awaiting me.

I have now had considerable experience in the breeding and rearing of Cheviot Sheep but in a hill country only, where it is impossible to tell the number of either of the sexes when lambed, or born as few of them require any assistance and we never have them in hand until the time of castration, however I do not think there can be much difference in the number of either of the sexes when lambed, but if the lambing season is cold and wet the male sex are more liable to die from having a greater tendency to a stoppage of the urine—1 My numbers this season at the time of castration were male 826 female 864

I remain Sir | Your obedt. servant | Jas. Oliver

George Cupples Esqre.


Oliver refers to what is now known as obstructive urolithiasis, a urethral blockage that is more common in male lambs, especially those that have been castrated.


Information about sexes of sheep at time of castration. Mortality of male lambs higher than that of females.

Letter details

Letter no.
James Oliver
George Cupples
Sent from
Howpasley, Hawick
Source of text
DAR 86: 67
Physical description
1p †

Please cite as

Darwin Correspondence Project, “Letter no. 6815F,” accessed on 2 August 2021,

Also published in The Correspondence of Charles Darwin, vol. 17