• Volume 76, Issue 1

      July 1972,   pages  1-38

    • Electron-probe microanalysis and geothermometry of sphalerite in the ingaladhal sulphide lode, chitradurga district, mysore state

      K V S Acharyulu C Borreswara Rao

      More Details Abstract Fulltext PDF

      Sphalerites coexisting with pyrrhotite and pyrite in Ingaladhal lode, Chitradurga District, Mysore State, were analysed for Fe, Mn, Cd, and S contents using an electron probe microanalyser. Four among the above samples were also analysed by X-ray diffraction using Cu-Kα radiation. Unit cell dimensions of sphalerites were calculated using Skinner’s equation. The iron content of sphalerite shows sympathetic variation with its temperature of formation. The estimated temperatures of formation of sphalerite, using Kullerud’s curve ranges between 340° C.–460° C. From the temperature measurements it is concluded that the ore body was formed at a single period of crystallization and that it would continue at depth.

    • Alkaline and acid phosphatases in the kidney of frog, lizard, bird and squirrel

      S V S Rana V P Agrawal

      More Details Abstract Fulltext PDF

      The phosphomonoesterases (alkaline phosphatase and acid phosphatase) have been localized in the kidney of frog,Rana tigrina, lizardHemidactylus flaviviridis, bird,Passer domesticus and squirrelFunambulus pennanti. Microscopical determination reveals a difference in the distribution of both enzymes in different classes. Though reptiles, aves and mammals have metanephros type of kidney but the localization of these two enzymes differs in different classes. As the main function of phosphomonoesterases is reabsorption of glucose from the tubules, it seems that this process is carried out at different sites in different vertebrates.

    • Effect of certain physico-chemical factors on the plankton of the nangal lake

      K K Tandon Harbans Singh

      More Details Abstract Fulltext PDF

      Physical factors such as temperature of air and water and penetration of light, and chemical factors like pH, total alkalinity, dissolved oxygen and phosphates were studied for one year. Maximum and minimum temperatures of air were recorded in June 1969 and February 1969 respectively and that of water in September 1968 and February 1969. Dissolved oxygen was maximum in May and June 1969 and minimum in October, 1968. pH did not show much variation. Penetration of light was maximum in April 1969 and minimum in June, 1969. Maximum total alkalinity was observed in October 1968 and minimum in August 1968. Phosphates were absent in October 1968. Maximum abundance of zooplankton generally followed the phytoplankton bloom.

    • New or rareHedyotis Linn. (Rubiaceae) from South India

      A N Henry K Subramanyam

      More Details Abstract Fulltext PDF

      Three taxa ofHedyotis Linn. (Rubiaceae), viz.,H. gamblei Henry & Subr. sp. nov.,H. eualata var.agastyamalayana Henry & Subr. var. nov. andH. barberi (Gamble) Henry & Subr. comb. nov., collected from Agastyamalai Hills and surrounding regions in Tirunelveli District, Tamil Nadu, South India, are described in this paper.

    • An evaluation of some techniques for isolation of rhizosphere and soil mycoflora

      K Natarajan

      More Details Abstract Fulltext PDF

      Different methods of isolation,viz., the dilution plate method, soil plate method and soil washing method were used in the present study with a view to obtain a fairly comprehensive picture of the mycoflora in the rhizosphere ofPennisetum typhoides and in the soil. In general, it was found that the dilution plate method gave more number of species than the soil plate method. The percentage occurrence of non-sporulating hyaline forms was more when the soil washing method was used compared to the other two methods. A larger number of Ascomycetes were obtained by the soil plate method than by the other two methods. A greater variety of fungi and a larger number of species were isolated by using all the three methods rather than one alone.


© 2017-2019 Indian Academy of Sciences, Bengaluru.