HISTOCHEMICAL REACTIONS OF THE LAMPREY MOUTH

¹ Harvard School of Dental Medicine, Boston, Mass.

1. A study has been made of the morphology of the lamprey mouth and the histochemistry of the keratinous and mucous products of the squamous epithelial lining of the oral mucosa.

2. An increasing degree of cornification has been demonstrated from the young tertiary caps to the functional primary caps of the lamprey teeth.

3. The beginning of this transformation is evidenced by the appearance of SH-positive granules in the cytoplasm of the squamous epithelial cells.

4. The appearance of these granules is accompanied by an intense alkaline phosphatase reaction in the nuclei of the squamous epithelial cells.

5. As cornification progresses from the tertiary to the secondary and primary caps, transition from SH groups to disulfide bonds can be demonstrated.

6. The transition from SH to disulfide reaction is accompanied by an increasing structural orientation of the fibrous protein. This is evidenced by a brilliant birefringence when the secondary and primary caps are examined under polarized light.