• Volume 65, Issue 6

      June 1967,   pages  231-279

    • Morphogenesis inArthrobacter species

      M F Mullakhanbhai J V Bhat

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      This paper presents data to show that arthrobacterial morphology depends upon the nature of nutrients in the culture media and the age of the cultures. Biotin has been shown to be a key nutrient affecting morphogenesis. Angular growth due to subpolar and bipolar germination and germination of two adjacent cocci have been indicated as the cause for the appearance of ‘V’ forms inArthrobacter. Life-cycle ofA. ruber n. sp. has been photomicrographically illustrated.

    • The sphyraenidae of the Indian coasts - I.Sphyraenella chrysotaenia (Klunzinger), 1884 andSphyraena qenie Klunzinger, 1870

      S Dutt B V Seshagiri Rao

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      Sphyraenella chrysotaenia (Klunzinger) andSphyraena qenie Klunzinger are recorded and described for the first time from Indian waters. Juveniles and adults of the former species occur at Visakhapatnam; adults were collected also from Porto Novo and Ernakulam. Adults ofS. qenie were collected from Visakhapatnam and Ernakulam.

      S. chrysotaenia can be distinguished from the related speciesS. flavicauda and fromS. obtusata by: (1) Deeper body; (2) Longer pectorals and ventrals; (3) Second dorsal spine being longer than first; (4) Distance from tip of depressed first dorsal to origin of second dorsal being less than snout length; (5) Elongated last rays of second dorsal and anal.

      S. qenie is distinguished by: (1) Absence of gill rakers; (2) Both dorsal fins and all or most anal rays being dark; (3) Maxilla reaching to vertical line through front of eye; (4) Absence of preopercular flap.

    • Embryological studies inCleome monophylla Linn.

      A V N Rao

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      InCleome monophylla Linn. calyx, stamens, corolla and carpels arise in acropetal succession. The wall of the anther has four layers of cells. The tapetum is binucleate and is of the glandular type. The cells of the endothecium have fibrillar thickenings. The microspores are tetrahedral, isobilateral and decussate in arrangement. The pollen-grains remain uninucleate mostly but rarely become binucleate at the time of shedding. Development of the female gametophyte in the bitegmic crassinucellate, campylotropous ovules conforms to the polygonum type. The embryo-sac becomes filled with starch-grains during later stages. The differentiation of testa and tegmen in the seed are described. The present observations are evaluated in the light of earlier investigations in the family.

    • Effect of the substitution of 3-methyl group on the carcinogenic activitiy of 2-naphthylamine

      M G Kanekar T B Panse G V Talwalkar

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      The carcinogenic activity of 3-methyl-2-naphthylamine (II) and its hydrochloride has been investigated with a view to studying the effect of 3-methyl substituent on the carcinogenic activity of 2-naphthylamine (I). It has been observed that:

      (1) Compared to compound (I), compound (II) is more carcinogenic to mice and rats. (2) Female rats are more susceptible than the male rats for the induction of tumour by (II) and its hydrochloride. (3) The subcutaneous injections of (II) induced fibrosarcomas in mice while the injections of its hydrochloride produced hemangioendotheliomas, local as well as at sites, distant from the site of application. From the biological activity of compound (II) it is inferred that the methyl group in (II) is involved in thein vivo carcinogenesis.

    • Structure and development of seedcoat in Cucurbitaceae - I. Seeds ofBiswarea Cong.,Edgaria Clarke, andHerpetospermum Hook. f.

      Dalbir Singh

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      The paper describes the development and structure of seedcoat inBiswarea tonglensis, Edgaria darjeelingensis, andHerpetospermum pedunculosum. The ovules are anatropous, bitegminal, and crassinucellar; they are horizontally disposed inBiswarea but pendulously inEdgaria andHerpetospermum. The ovular supply is unbranched inBiswarea andHerp etosperumum but ramifies in the lower part of seed inEdgaria. The outer integument alone forms the seedcoat which, at maturity, is differentiated into five zones. The epidermis is heterogeneous consisting of upright cells in all these plants. The hypodermis is sinuate, cells thick-walled and lignified; it is 10 to 14-layered in furrows and 20 or more-layered in ridges inBiswarea, 5 or 6-layered in furrows and 8 to 12-layered in ridges inEdgaria, and 2 or 3-layered in furrows and up to 10-layered in ridges inHerpetospermum. The main sclerenchymatous layer consists of osteosclereids. The seedcoat in all these plants is built on a common pattern and suggests a close relationship among them. A key is proposed to distinguishBiswarea, Edgaria andHerpetospermum from each other using external and internal characters of their seeds.

    • Colchic ineinduced chromosome mosaic inSorghum vulgare L.

      E A Siddiq

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      One of the colchicine treated plants was found to be a chromosome mosaic having different sets of chromosomes in different microsporocytes of the same anther. Morphologically the plant resembled a haploid by having reduced height, narrow and short leaves and proportionately reduced size of floral parts. Three types of pollen-grains,viz., large, medium and small, all of which were invariably sterile were observed. Origin of hyperploid cells, phenomenon of univalent association in haploid cells and cause of difference in the pollen-grain size have been discussed.

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