Abnormal Growths associated with Wool Follicles in Sheep

Abstract

Burns and Clarkson1 described ‘capsules’ in sheep skin which, when traced up towards the skin surface, were apparently degenerate follicles. Similar roughly spherical bodies have now been seen free in the dermis. These usually had lumina like the ‘capsules’ mentioned above and, although smaller, could presumably have arisen from degenerate follicles by disruption at a point on the longitudinal axis of the follicle. Thus, when in samples taken at different ages from various sheep breeds, these bodies were observed attached to the base of an otherwise normal follicle, usually not far above the bulb (Fig. 1), they were thought to have become secondarily attached. However, in this figure the connective tissue sheath can be seen to be split and ‘pushed away’ from the follicle, and in preparations stained with cyanol to show blood vessels2 the capillary network of the follicle has been seen to extend around these bodies. This suggests that the body had, in fact, been formed as an outgrowth from the follicle and had not become secondarily attached. When one was seen in a sheep vibrissal follicle within the blood sinus, the suggestion of secondary attachment seemed untenable.