The pituitary of the African lungfish Protopterus sp.

Abstract

In general structure, the distal lobe closely resembles that of an amphibian, whereas the elaborate intermingling of nervous and intermediate lobes recalls the typical fish condition. In cell types, the majority of the intermediate-lobe cells have the same reactions as in amphibians but there is in addition another cell type which appears to be unique. In the distal lobe there are three types of basophils and two of acidophils, in many respects resembling the same five cell types found in amphibians. Developmental stages help to explain the structure of the neural-intermediate complex.