A HISTOLOGICAL STUDY OF THE ORGANIZATION OF THE RUMEN EPITHELIUM OF SHEEP

¹ The Rowett Research Institute, Bucksburn, Aberdeenshire

1. The papillæ of the surface of the rumen of sheep have been shown to have a rich blood and lymphatic supply in intimate contact with the basal layer of the stratified squamous epithelium.

2. The basal layer of the epithelium consists of columnar cells which in the papillary bodies are arranged round the capillaries, the long axis of the cells being perpendicular to the length of the capillaries. Cells similar to "prickle" cells of the skin are present in the transitional layer between the basal columnar cells and the outer keratinized layers.

3. Mitochondria, which have been shown to be very numerous in the columnar cells, are often elongated and orientated in the long axis of the cells.

4. An analogy between the cubical epithelium of the convoluted tubules of the kidney and the columnar cells of the rumen epithelium is suggested.

Note:

The authors wish to thank Dr. W. G. Bruce Casselman and Dr. Barbara M. Jordan for advice on the use of Metzner's method, and Messrs. J. B. Bruce and C. D. Pollock for help with the photomicrographs.