• R Nagabhushanam

      Articles written in Proceedings – Section B

    • The rate of water filtration in the marine wood-boring mollusc,Martesia striata linn

      R Nagabhushanam

      More Details Abstract Fulltext PDF

      1. The Neutral Red technique was employed to study the filtration rates ofMartesia striata.

      2. It appears that low salinity has a great depressing effect upon the rate of filtration inMartesia.

      3. Light has got no effect on the filtration rate.

    • Neurosecretion in the central nervous system of the hermit crab,Diogenes bicristimanus

      R Nagabhushanam R Sarojini

      More Details Abstract Fulltext PDF

      1. A detailed morphological description of the neurosecretory cells in the hermit crab,Diogenes bicristimanus, is given. The eyestalks ofDiogenes contain secretory bodies namely the Z-organs. Each Z-organ is located at some distance from the basement membrane of the compound eye encircling the optic peduncle. The Z-organs show secretory activity which follows that of the moult cycle.

      2. The optic ganglia and sinus gland are incorporated within the brain.

      3. Three types of neurosecretory cells, designated as A, B and C, are encountered in the central nervous organs other than the eyestalks. They are distinguished by their sizes, the nature of the nuclei, vacuoles and the secretory products in the cytoplasm. All the three cell types occur in the supraoesophageal ganglia, thoracic ganglion and abdominal ganglia while the commissural ganglia possess only A and B cells.

      4. The secretory products appear to be discharged through the axons. The direct discharge of secretions into the blood capillaries surrounding the cells is also noticed.

    • Neurosecretion in the slug,Laevicaulis alte

      R Nagabhushanam A B Kulkarni

      More Details Abstract Fulltext PDF

      1. The detailed morphological structure of neurosecretory cells inLaevicaulis is given. There are two types of cells: cell type A is pyriform ranging from 83 to 133 µ in length, whereas cell type B is oval and is 49 to 66 µ in length. In both the cell types axonal transport of the secretory material is noticed. Both the cell types are PAS negative and positive for proteins and lipids.

      2. Histological structure of the optic tentacle reveals that it consists of three types of neurosecretory cells of which the collar cells are situated around the central ganglia while the others are laterally down the sides of dermo-muscular wall. They are PAS positive and sudanophilic.

      3. Cell type B showed a distinct annual cycle of activity which is correlated with the annual reproductive cycle ofLaevicaulis.

      4. The effect of cutting the tentacles showed that number of eggs was increased in optic tentacles-cut animals. The tentacle homogenate injected animals showed no increase in number of eggs but the brain homogenate injected animals showed considerable increase in the number of eggs.

      5. The amount of neurosecretory material in cell type A decreased from lower to higher salt concentrations. It may conclude that cell type A plays an important role in water balance as anti-diuretic factor.

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