The present paper describes the post-natal character and its development of the hair follicle group which is a fundarnental unit of the fleece, in the skin of lambs of the Corriedale breed.
The tested arlimals were four Corriedale lambs and the skin samples of the lambs were removed from three different regions of each lamb at four stages, namely at 1, 3, 6 and 9 months after birth and then the histologioal sections of the skin sam-ples were prepared for microscopical examination.
The results obtained are as follows:
(1) It is suggested that the hair follicle population of the skin of lambs is generally composed of prinmary group (one primary follicle and its associated secondary follicles).
The primary group, therefore, may be regarded as a fundamental unit of the fleece and in the majority of samples most of the primary groups are arranged in trio group.
(2) Normally one primary follicle is leen on one side of a follicle bundle and the secondary follicles corresponding to each primary follicle are grouped around its ectal aspect.
In general on the other side of the follicle bun-dle a few of very large follicles are present, and little secondary follicles in the center of the bundle.
(3) Each of primary follicles has a sebaceous gland, a sudoriferous gland and an arrector muscle, while a secondary follicle usualy has a sebaceous gland, but not a sudoriferous gland and an arrector muscle.
(4) The presence of a few of young secondary follicles whose fibers are not yet long enough to constitute to the fleece is recognized in skin samples taken at 1 and 3 month of age.
(5) The fibers of all follicles are probably constituting the fleece within 6 months after birth, so that the fleece may be considered to have become established in Corriedale lambs within 6 months after birth.
(6) The empty follicles in which shedding occured are found on each of skin samples at 1, 3, 6 and 9 months of age and a considerable numder of shedding follicles are observed on the skin samples of lambs 6 months old,
(7) The average follicle size increases with advancing ages up to ninth month after birth, the last skin sampling month.
抄録全体を表示