• Volume 69, Issue 4

      April 1969,   pages  185-233

    • Floral colours and their origins

      C V Raman

      More Details Abstract Fulltext PDF

      A new orientation is given to the subject of floral colours by the author’s discovery that these colours may be placed into two distinct spectral categories, which have been designated by him respectively as the spectrum of florachrome A and of florachrome B. Typical of these two categories are the colours ofDelphinium ajacis (larkspur) in the blue and pink varieties respectively, the former showing the spectrum of flora-chrome A and the latter that of florachrome B. As a general rule, all blue flowers exhibit the spectrum of florachrome A which consists of three distinct and clearly separated bands of absorption appearing respectively in the red at 630 mµ, in the yellow at 580 mµ and in the green at 540 mµ. The spectrum of florachrome B also consists of three distinct bands of absorption, but these now appear in the orange-yellow at 590 mµ, in the green at 545 mµ and in the blue-green at 505 mµ. Spectra exhibiting these features are reproduced with the paper. Their explanation is discussed and it is shown that they owe their origin to an electronic absorption frequency located at the first of the three bands combining with vibrational transitions, the oscillator being the CO group present in the structure of the florachrome.

    • The prothallus ofPolystichum

      B K Nayar Surjit Kaur Prakash Chandra

      More Details Abstract Fulltext PDF

      In the 9 spp. ofPolystichum studied, a uniseriate germ filament is produced on spore germination. The anterior cells of the germ filament develop into a prothallial plate commonly before or sometimes after the terminal cell develops a papillate hair. A meristematic cell is differentiated early during plate formation, commonly in one of the daughter cells of the terminal cell or rarely (when the terminal cell is quiescent and hair-bearing as inP. aculeatum andP. lentum) of the penultimate cell. Young thalli become cordate inc. 8 weeks from spore germination and fully grown inc. 3 months. The mature prothallus is profusely hairy and cordate with a thick midrib and spread-out wings. Hairs are of the capped, unicellular, papillate type; a few club-shaped, unicellular hairs devoid of terminal caps are found in addition on the anterior margin. Sex organs are of the usual leptosporangiate type. The antheridium dehisces by a pore-like opening formed in the cap cell.

    • On a new trematodeDiplodiscus chauhani N. Sp. from the common Indian frog,Rana cyanophlyctis Schneider

      K C Pandey

      More Details Abstract Fulltext PDF

      Diplodiscus chauhani n. sp. has been described fromRana cyanophlyctis Schneider at Gyanpur, Varanasi. The species is characterised by the absence of oral pouches, the oesophageal bulb and by the pattern of the excretory system.

    • Note on fungi of Jammu and Kashmir—II

      V R Pandotra K S M Sastry

      More Details Fulltext PDF
    • Calc-silicate rocks and charnockites from Kasimkota area, Visakhapatnam district, A.P.

      A V R Sastry R S N Murty

      More Details Abstract Fulltext PDF

      Khondalites, leptynites, charnockites, hypersthene-granulites, diopside-gneisses and calc-silicate rocks outcrop conformably in a small area, which is seven kilometers away in the north-west direction from Kasimkota Railway Station. The close association of charnockites with diopside-gneisses and calc-silicate rocks particularly in the Eastern Ghats is of great importance to the elucidation of the charnockite problem.

      The constituent minerals of these rocks are diopside-hedenbergite, diopside-aegirine, bronzite-hypersthene, plagioclase, garnet (grossularite), titanite, wollastonite and quartz. Apatite and biotite are present in accessory amounts. Rounded zircons and microcline are found only in a few rocks.

      During regional metamorphism of impure calcareous sediments, various stages of reconstitution of minerals are found. From the petrographic investigations, it is surmised that garnet, titanite and hypersthene are developed by the reaction between diopside and anorthite. Garnets of second generation are found to have grown with the earlier garnets as their neuclei and also as intergranular veinlets at the expense of scapolite. These reactions are represented by equations.

      Metatectic quartz and plagioclase, diatectic biotite and opaque ores, alkali metasomatism are considered to be the different facets of manifestation of anatexis in this area.

    • A collection of brachionid rotifers from Kerala

      C K G Nayar K K N Nair

      More Details Abstract Fulltext PDF

      The present paper, which deals with 15 species of brachionid rotifers, forms the first report on the rotifers of Kerala. A new varietyBrachionus forficula keralaiensis has been described.Dipeuchlanis propatula, Anuraeopsis fissa lata andBrachionus caudatus personatus are reported for the first time from India.


© 2017-2019 Indian Academy of Sciences, Bengaluru.