The pre-natal development of follicle population in the Romney lamb

Abstract

Previous studies on the development of follicle population in relation to the growth of the fleece have, except for the Merino, been mostly post-natal. The pre-natal study of follicle development in some British sheep by Wildman (1932) was mainly qualitative, as also was the work of Carter (1943) in the Merino. The latter study was, however, followed by some numerical work on the same breed (Carter & Hardy, 1947). Figures were given for the follicle density per unit area and the ratio of the number of secondary follicles to the number of primaries at different ages. The present study therefore helps to fill a gap in our knowledge by considering numerically the pre-natal stages of development in the English Romney, a breed which is important in the northern hemisphere and which might be considered to be comparable with the Romney of the southern hemisphere.