Quinlan, John; Myburgh, S.J.; De Vos, D.; Du Toit, P.J.(Pretoria : The Government Printer, 1941)
(1) The pH of the vaginal secretion of mature merino ewes, measured during
oestrus, gave a mean value of 6·648, with a range of 5·85 to 7·40. During
mid-dioestrus the mean value was 6·694, with a range of 6·00 to 7·60. ...