THE ADRENAL GLAND IN NEW-BORN MAMMALS. By Geoffrey Bourne, D.Sc, Australian Institute of Anatomy. (Plate xi; twenty Text-figures.) [Read 30th September, 1936.] For this work the adrenals of the following species were examined: (1) Two new-born specimens of Equus zebra; (2) one new-born Ursus maritimus (Polar Bear) ; (3) one young specimen (a few weeks old) of Arctocephalus doriferus (Seal); (4) one late foetus of Delphinus delplius (Dolphin); (5) one ten-inch pouch-embryo of Dendrolagus oennettianus (Tree Kangaroo) ; (6) one ten-inch pouch-embryo of Macropus giganteus (Kangaroo) ; (7) one four-inch female and one five-inch male pouch-embryo of Macropus ruficollis; (8) one young female specimen of Macropus agilis. The two young zebras were obtained by courtesy of the Zoo authorities in Western Australia, and other glands described were obtained from preserved specimens in the possession of the Australian and National Museums, and the Western Australian Museum. As a result of the imperfect fixation of the glands in the museum specimens, accurate details regarding the cells could not be given, but it -was possible to distinguish the various zones and to make some degree of comparison with other forms. Fixation and Staining. The adrenals of the zebras were removed and divided into various sections. One portion was placed in 10% formalin for two days, then washed, imbedded, and sectioned. The sections were stained by the haemalum-eosin method. Other sections of the zebra adrenal were treated in various ways. A portion was fixed in formalin for 24 hours; frozen sections were treated with Scharlach R and Sudan III to demonstrate fats and lipoids, and then mounted in glycerine jelly. Another portion was treated with osmium tetroxide (osmic acid) to test for the presence of unsaturated fat. In addition a portion of one gland was fixed in a mixture of 3% potassium bichromate 2 parts, 1% chromic acid 2 parts, and 2% osmic acid 1 part, for twenty-four hours, then placed in 2% osmic acid for four days at 30° C. (Kolatchev's method) ; the resulting sections demonstrated the Golgi apparatus. For mitochondria another piece of gland was placed in the above fixative for twenty-four hours, washed, mordanted for six days in 3% potassium bichromate, washed, and sectioned. The sections were stained by the classical acid-fuchsin-picric-acid method. The Staining of the Vitamin C. Of two further pieces of gland, one was placed in the present author's modification of Giroud and Leblond's acetic acid silver nitrate mixture for two hours in the dark and kept at room temperature. Another piece was placed in acetic acid gold chloride for a similar time and under identical conditions. The composition of the silver nitrate solution was 2% silver nitrate with 5 c.c. of
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