• Volume 27, Issue 5

      May 1948,   pages  119-151

    • Isopod parasites of free-living copepods of Madras

      C P Gnanamuthu S Krishnaswamy

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    • The effect of asphyxia on the mechanical response of the frog’s unstriated muscle and its relation to tonus

      Inderjit Singh Sunita Inderjit Singh

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      1. Asphyxia at first increases the response of frog’s unstriated muscle; this is followed by diminution and then paralysis. These effects are also produced by cyanide. This increase in excitability is not abolished by iodoacetic acid.

      2. Asphyxiai arrest is relieved by glucose, potassium and the other substances that produce tonic contraction.

      3. In the presence of oxygen the muscle becomes hyperirritable in acid solutions and so possesses different aerobic metabolic mechanisms in alkaline and acid solutions respectively.

      4. In acid solutions, pH 6, sodium lactate, acetate and propionate improve the response to alternating current.

      5. Asphyxia does not produce rapid arrest of movement in muscle poisoned with iodoacetic acid.

      6. In a muscle poisoned with iodoacetic acid, then exhausted by frequent stimulation in asphyixia, and then revived by oxygen, sodium lactate and sodium butyrate improve the response. Glucose, glycine, sodium acetate and propionate have no effect.

      7. In asphyxia, tone at first decreases and then increases; this asphyxiai contraction is identical with tone that does not use oxygen.

    • Studies on the embryology of microchiroptera - Part II, reproduction in the male vespertilionid batScotophilus wroughtoni (Thomas)

      A Gopalakrishna

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      1. Twenty-nine male specimens of the batScotophilus wroughtoni were collected during the different months of the year. Collection were made during two successive years from May 1945 to April 1947.

      2. The weight of the testis of these bats increases from the month of December and reaches a maximum weight during February. There is an increase nearly four times in the testis-weight from September to February.

      3. The diameter of the seminiferous tubules also increases corresponding to the increase in the testis-weight and progressively vigorous spermatogenetic activity is seen in the germ cells. The diameter of the tubules of the epididymis also increases during’ these months. The occurrence of sperms in the tubules of the testis and the epididymis indicates that the breeding season is confined to these months.

      4. The males, like the females, probably attain their sexual maturity in their first season,i.e., before they are one year old.

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