The Structure and Development of the Nasal Glands of Birds
*Communicated by Prof. Graham Cannon, Sc.D., F.Z.S.
- 1The anatomy, histology, and development of the nasal glands are described in several species of birds belonging to seven orders.
- 2The position of the glands, above the orbits, the course of the ducts, and the arrangement of the nerves and blood-vessels are very similar in different species.
- 3There are two glands and ducts on each side, one duct opening on the niedian and the other on the lateral wall of the vestibule.
- 4In marine species the glands consist of tubules, on all sides of which glandular diverticula radiate out.
- 5In terrestrial species the glands are reduced in size, in number of tubules, and especially in the number of the glandular diverticula.
- 6The secretion consists of a slimy mass of degenerating cells.
- 7The glands are much better developed in marine than in freshwater species, so apparently an important function of the secretion is to protect the lining of the nasal cavity against the effects of sea-water.
- 8In development the ducts grow back from the epithelium of the nasal vestibule as solid strands, and branch to form the tubules of the gland. The lateral glandular diverticula arise as outgrowths from the branches of the ducts.
- 9The glands are homologous with the nasal glands of other vertebrates, and are not connected in any way with Jacobson's Organ.
- 10The Galliformes, alone amongst the orders which have been investigated, have only the median duct opening on the septum. There is no trace of the outer duct during development in the Fowl. It is suggested that this may be of use in classification.
- 11A summary is given of the past work on the nasal glands of birds, most of which has been on their possible connection with Jacobson's Organ.