Development of the follicle population in N-type sheep.

Abstract

The development of the follicle population in N-type sheep is described for the period from 40 days of gestation to birth. No major differences from the description given for the non-N-type Romney or the Merino were found. The development and growth of follicles after their first initiation appear to be slightly faster in N-type. The tips of fibres which had pierced the skin at 113 and 119 days' gestation were examined and found to belong to all birthcoat fibre types except hiserotrichs. Since it has been shown that secondary follicles form, in addition to histerotrichs, only curly-tips, it follows that primary follicles form some types of fibres which do not grow in secondary follicles.