• Volume 54, Issue 5

      November 1961,   pages  209-256

    • Additions to our knowledge of Indian soil fungi

      J N Rai J P Tewari

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    • Root apical organization in monocotyledons—Palmeae

      S K Pillai Ambuja Pillai

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      The root apical organization of seven species belonging to six genera of the family Palmeæ has been investigated and reported.

      The structural organization in these species falls under three types, one with a common group of initials for all the histogens, the second where the initials are common for the dermatogen and calyptrogen while the rest arise from a common group at the centre, and a third, where there are independent initials for plerome and root-cap and a common tier for the dermatogen and periblem.

      On the basis of this, a tentative suggestion is made regarding the evolutionary trend of the root apical organization in these.

      The cell complexes are analysed.

      The meristem concerned with the formation of the two parts of the calyptra is distinguished into two zones, the peripheral region outside and the columellogen in the centre, on the basis of the types of cell division.

      The endodermis is traced in its origin to an endodermis-periblem complex.

      The cyto-physiological state of the cells at the root apices when studied showed that a quiescent centre is present at the extreme tip of the root body. This is surrounded on the side of the root body by a group of cells which appear to be the real site of histogenetic activity, named the meristematic zone.

      The inadequacy of limiting the study of root apices to the structural configuration alone, and of combining it with other aspects like the cytophysiological state of the cells, is once again exemplified.

    • Root apical organization in monocotyledons—Xyridaceæ

      S K Pillai Ambuja Pillai

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      The root apical organization of two species ofXyris has been investigated.

      The structural configuration shows discrete initials for plerome and rootcap and a common tier of initials for the epidermis and cortex.

      The cell complexes are analysed.

      The endodermis arises from an endodermis-periblem complex.

      Cyto-physiologically there is a quiescent centre to the tip of the root body with the real histogenetic zone, named the meristematic zone, surrounding it. The characteristics of these two zones are described.

    • Effect of temperature and humidity of the fecundity and longevity ofChelonus rufus lyle (Braconidae: Hymenoptera)

      B R Subba Rao G K V Gowda

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      Chelonus rufus Lyle is an egg larval parasite of the cotton bollwormEarias spp. in India. Investigations on the effect of temperature and humidity on the fecundity and longevity of the parasite have been studied.

      1. Temperature has a profound influence on the fecundity, longevity and oviposition days of the parasite.

      2. Maximum fecundity is obtained at 30°C., and lower and higher temperatures greatly reduced the number of eggs laid.

      3. Optimum temperature for the longevity of the female is 25°C., though there is not significant difference between 25 and 30°C. in this respect. However, at 15°C., the longevity is increased to three times, but the fecundity is very much reduced. At 40°C. the longevity is about four times less than that at optimum temperature.

      4. Daylight or darkness do not affect the fecundity.

      5. Humidity and the interaction between relative humidity and temperature has no marked effect on both fecundity and longevity of the female.

    • A study of blood of a few Indian fishes - I. Haemoglobin

      Vidya Pradhan

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      The values for hæmoglobin, hematocrit and red blood corpuscles are determined for the blood ofTilapia andOphiocephalus. The hæmoglobin values ofMegalops, Macrones, Sacchobranchus andPeriopthalmus are also given for comparison.

      The hæmoglobin values range from 6·5–12 gm./100 c.c. in general;Ophiocephalus andPeriopthalmus show higher values, namely 12–19 gm./100 c.c.

      The R.B.C. count is lower than mammalian blood. But the hematocrit values are high. Therefore the mean corpuscular volume and mean corpuscular hæmoglobin is high.

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