Digestive physiology ofBradynopyga geminata (Odonata: Libellulidae)

Summary The pH of the gut ofB. geminata ranges from 5.5 to 6.8. The midgut is the main source of the digestive enzymes, secreting trypsin-like protease, chymotrypsin, aminopeptidase,a-amylase, maltase, sucrase, lactase and lipase.     

Orientation ofPapilio demoleus larvae to coloured solutions

Summary The present work compares the taxis ofPapilio demoleus larvae to different coloured solutions. The larval positive taxis, i.e., attraction, is maximum for yellow colour and declines with the increase or decrease in the wavelength of maximum light transmission. Red and bluish-green colours repel the larvae.     

Trypsin activity in the hepatopancreas ofMacrobrachium lamarrei (Crustacea: Decapoda)

Summary Trypsin from the hepatopancreas ofMacrobrachium lamarrei showed optimum activity at pH 7.5 and temperature 45°C. The enzyme activity increased with the increase in incubation period and enzyme concentration. Michaelis constant of the enzyme was 2.38×10^–2 M.Acknowledgments. The authors are thankful to University Grants Commission, India for the award of a Junior Research Fellowship.     

Amperometric study on lanthanum polytungstates

Zusammenfassung Es wurde die Zusammensetzung von Lanthanwolframat-Niederschlägen untersucht, die sich aus Lanthannitrat- und Natriumwolframat-Lösungen verschiedener Polymerisationsgrade bilden. Die Reaktionen wurden bei verschiedenem pH, in rein wässrigem oder wässrig-alkoholischem Milieu durch amperometrische Titration verfolgt. Im pH-Bereich von 5,5–6,5 bildet sich La₂O₃ · 3WO₃, bei einem pH von 4,2–5,5 La₂O₃ · 7WO₃.

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Acknowledgment: O. P.Sharma is grateful to the Council of Scientific and Industrial Research, New Delhi, for financial assistance and to Principal V. G.Garde for providing research facilities.     

Histochemical localization of alkaline and acid phosphatase activities in the skin ofMystus (Mystus) vittatus Bl. (Siluriformes)

Summary An attempt has been made to localize alkaline and acid phosphatase activities in the skin ofMystus vittatus by using histochemical techniques. The alkaline phosphatase activity is found in metabolically active cells such as basal columnar cells, mucous cells and polygonal support cells. The acid phosphatase activity is intense in the outermost squamous support cells and in the basal columnar cells. These activities have been correlated with some physiological functions of the epidermis.Acknowledgment. We are thankful to P. Vishwanatham, Government College, Mhow, and Dr R.S. Shrivastava, Holkar Science College, Indore, for providing laboratory facilities and to the Council of Scientific and Industrial Research, New Delhi, for a fellowship for M.S.     

Mode of action of acorus calamus L. oil vapours on adult male sterility in red cotton bug

Summary In normal freshly moulted insects Spermotozoa are present and pass into the vas deferens after 24 h. They show morphological changes when inside the female genital tract. Sterility caused by Acorus calamus oil vapours is due to agglutation, malformation and immobility of sperms, which makes the sperms unable to undergo morphological differentiation in the female tract.     

Morphological changes inThermobia domestica under the influence ofAcorus calamus oil vapours

Zusammenfassung Eine Behandlung der Weibchen vonThermobia domestica mit den Dämpfen eines Extrakts der WasserpflanzeAcorus calamus L. bewirkte dauernde Sterilität, da die Oogonien und präfollikulären Zellen in den Germarien und die follikulären Zellen und Oozyten in den Pävitellarien zerstört wurden. In manchen Fällen wurde die Tunica propria zerstört, was zur Unterbrechung der Ovariolen führte.