Open AccessThe development of the thymus, epithelial bodies and thyroid in the marsupialia. Part I.—Trichosurus vulpecula
Author(s) -
Elizabeth A. Fraser,
J. P. Hill
Publication year - 1915
Publication title -
proceedings of the royal society of london. series b, containing papers of a biological character
Language(s) - English
Resource type - Journals
eISSN - 2053-9185
pISSN - 0950-1193
DOI - 10.1098/rspb.1915.0031
Subject(s) - anatomy , thyroid , biology , endocrinology
In recent years much attention has been paid to the development of the thymus and thyroid glands in the higher Mammalia but no observations on the development of these structures are extant in the case of the Marsupialia. In this memoir the authors have attempted to fill this blank in our knowledge so far as the Diprotodont Trichosurus is concerned. They have had at their disposal an extensive material of that form comprising both uterine and fœtal specimens, grouped in 22 stages. In the adult, the thymus is remarkable in that it consists of three pairs of glands, viz., a large paired superficial cervical thymus situated posteriorly to the submaxillary salivary glands and internally to the platysma on the ventral side of the anterior region of the neck, and two pairs of smaller thoracic or posterior cervical glands, situated the one behind the other, cranially to the pericardium and in relation to the corresponding common carotid arteries. These latter glands represent respectively paired thymus III and IV. They may remain separate or the two glands of the same side may unite with each other on one or both sides of the body.