A Comparative Study of Some Teleost Pituitaries.


  • Communicated by Prof. E. A. Spaul, F.Z.S.


  • 1 A series of pituitaries of teleosts from a number of orders have been examined. A nervous lobe and a glandular component of three regions, typically confluent but distinct, is present in all.
  • 2 The form of the nervous lobe and its penetration into the glandular regions is described, and the variations in the relations of the various parts to each other and to the brain. Their histological features, blood supply, relative sizes and degree of confluence, and their diagnostic characters are summarized.
  • 3 Systematic position has been found to entail a considerable degree of similarity in the glands as far as orders and families are concerned, but it is only possible to trace the evolution of the gland within the group to a very minor extent.
  • 4 The homology of the various subdivisions of the gland with those of higher types is indicated and a possible relationship between them through lung-fish and ganoids is suggested.