Monthly coat and skin samples were taken from three goats for one year in Australia, and from six others for two years in Scotland. The coat appeared to have a simple cycle of active growth in summer followed by inactivity in winter.The kemp fibres of the outer coat formed brush ends at about the time of the autumn equinox and remained dormant until late spring. Follicles developed first in the foetus formed a brush first. No moult was obvious because new kemps grew before all the old ones had shed, the only manifestation of shedding being a shortening of the coat. The old wool tended to be lost before growth of the new, so that wool was completely lacking in the coat during summer.Observations on skin sections showed that the majority of both kemp (primary) and under-wool (secondary) follicles become active immediately after the longest day, although there was a tendency for re-growth of wool fibres to be delayed, particularly in females.Whereas the proportion of kemps with brush ends during winter reached 100%, the proportion among wool fibres was as low as 50%. A complete explanation for this is not yet evident. The bad winter of 1963 apparently caused a greater proportion of secondaries to form brush-ends earlier and to remain inactive longer.Details are given of some of the histological features of brush formation.

Link to this article: http://journals.cambridge.org/ abstract_S0003356100028476 How to cite this article: M. L. Ryder (1969). The development and structure of, and seasonal change in, the coat of some Wiltshire sheep. SUMMARYCoat and skin samples were taken monthly from three Wiltshire ewes for two years, and then fortnightly between the spring equinox and the autumn equinox of 1968. The fleece comprised kemp and wool, having a weight of 1-1 kg and a length of 50 mm. In summer all the primary fibres had a latticed medulla, and although the secondaries were smaller than the primaries, they were relatively coarse and often medullated, over onethird having a latticed medulla at the peak period. The overall mean S/P ratio was 3-5.

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The wool growth cycle in six rams and eight ewes was studied by taking monthly coat and skin samples for 3 years from each. Coat length was measured, and the percentage of inactive follicles was noted as well as the percentage of medullated fibres.In the spring moult 'mainland' sheep (stock removed from St Kilda 60 years ago) cast less completely than 'St Kilda sheep' (Soays removed more recently from St Kilda). Mainland rams cast less than the ewes, but St Kilda rams began casting earlier, and completed casting more quickly than the ewes. Despite differences between years in the rate of casting, similarities in the pattern of casting were observed between years in the same animal, and between parent and offspring.This apparent annual cycle was confirmed by graphs of follicle inactivity which showed that most inactivity occurred from September to March in the rams, and from October to April in the ewes. It was possible to fit sin and cos waves of 12-month duration to the graphs and further analysis revealed superimposed a 6-month cycle in one group, and a 4-month cycle in another group, which were associated with subsidiary peaks of inactivity in the summer. There were suggestions of a cycle about 2 months in length throughout the year, and sin waves of this duration could be fitted to the data from one of the groups of ewes. Possible control mechanisms for the annual and shorter cycles are discussed.Peaks of follicle inactivity were frequently followed by troughs in coat length which suggested actual loss of the longest fibres.Medullation was absent or minimal from December to March, and there were two peaks during the period of maximum medullation, that in the spring being greater than the one in the autumn. INTRODUCTIONMATERIALS AND METHODS

We report a family of six individuals with an abnormality of scalp hair characterized by shorter, finer, kinky hairs interspersed with normal hair, throughout the scalp. The abnormality had gone unnoticed in four of the six individuals. Two complained of thinning of the scalp hair.