CYTOLOGICAL EVIDENCE FOR A ROLE OF THE CORPUSCLES OF STANNIUS IN THE OSMOREGULATION OF TELEOSTS

¹ The American Museum of Natural History, New York 24, New York

1. The effects of DCA, pitressin, water, and sodium and potassium chloride on the cytology of the corpuscles of Stannius were studied by means of Baker's acid hematein stain for phospholipids. The fresh water characin Astyanax mexicanus was used.

2. Two kinds of changes in the cells of the corpuscles were brought about by the experimental procedures: degranulation, loss of cytoplasm and consequent decrease in size of cells accompanied the administration of potassium chloride, undiluted pitressin and long continued immersion in 1% sodium chloride, and hypertrophy of cells with increase in numbers and size of blackened granules accompanied the administration of water, diluted pitressin and DCA.

3. Loss of staining reaction in mitochondria of kidney tubules was associated with increased secretory activity in the corpuscles of Stannius except in the case of long continued DCA administration and administration of pitressin.

4. The results are interpreted as indicating a function of the corpuscles of Stannius in the osmoregulation of these fish possibly connected with excretion of excess water.