The Physiology of the Antennal Gland of Carcinus Maenas (L.)

Abstract

1. U/B ratios for inulin and sorbitol have been measured in 100%, 75% and 50% sea water. 2. When Carcinus is in 100% sea water, a U/B ratio of 1 for both sorbitol and inulin is reached and maintained after 40 and 115 hr. respectively. A reason for this difference is suggested. 3. In dilute media the rate of increase of U/B ratio for both molecules is more rapid than in 100% sea water. For instance, in 50% sea water the inulin U/B ratio is 1 after 50-60 hr. Sorbitol ratios are generally less than 1 in dilute sea water and a possible explanation of this is given. 4. In any particular concentration of sea water blood and urine concentrations of injected solutes fall at approximately the same rate once the maximum urine concentration has been reached. 5. It is concluded that primary urine production in Carcinus is by a filtration mechanism and that reabsorption of water from the urine does not normally occur.