Abstract
The subneural gland of the ascidian has long been the subject of controversy in regard to its probable function. On developmental grounds it has been denied admission to phylogenetic series dealing with the pituitary and until quite recently there has been no physiological evidence which might justify including it in such a series on a functional basis.
Butcher 1 demonstrated the presence of the oxytocic principle in the gland of Molgula and this result suggested the possibility of obtaining other pituitary effects such as the ovarian stimulating action in immature animals. The present work deals with an attempt to demonstrate such an effect using the gland of the large solitary ascidian Polycar pa tecta common in Bermuda waters.
In 1934, through the courtesy of the Bermuda Biological Station for Research, 70 fresh specimens of Polycarpa tecta were obtained and the ganglion, subneural gland and dorsal tubercle removed and desiccated in acetone. The dry weight was found to be 45 mg. and from a study of serial sections it was apparent that not more than 20–30 mg. of this weight could be considered glandular substance. Assuming a potency equal to that of mammalian whole gland it was not thought advisable to divide the material among more than 3 test animals. Accordingly, after pulverization and suspension in sterile isotonic saline equal amounts were injected subcutaneously into 3 nineteen-day-old mice. Three control animals received subcutaneous saline. None of the animals died and all were killed and autopsied on the fifth day.
Grossly the ovaries of the test animals were larger and appeared more vascular. The collective weights to the nearest milligram compared as follows: Test, 25 mg.; control, 8 mg.
Microscopic examination of the ovaries showed an increase in vascularity arid in the nuniber and size of the follicles in the test specimens. (Fig. 1.)
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