Volume 60, Issue 2
August 1964, pages 81-161
pp 81-86 August 1964
pp 87-94 August 1964
Fertilization is porogamous. The embryogeny falls under Group 1 of Series A of Grand Period I according Souèges’ system but the organization of quadrant fromca differs from that ofCoronilla minima which is described as the type under this category. The embryo development follows the Onagrad type but does not conform to any of the known variations under this type in the system of Johansen. Therefore, a new variation to be called as Aeschynomene variation under the Onagrad type, is proposed to accommodate the present species.
The endosperm is first nuclear and then cellular. Ultimately, it is completely absorbed by the developing embryo. The mature seed is thus non-endospermous. The mature testa consists of all the layers of the outer integument and one or two layers of the inner integument.
pp 95-106 August 1964
In different species ofJatropha examined a profusely branched system of non-articulated laticifers is found distributed in different plant organs. They originate in the embryonic stage from certain initials and keep pace with the growth of the plant. A few laticifers may also arise independently from spongy mesophyll cells in the leaves. The laticifers are present in all the parts of the plant chiefly occurring in the vicinity of vascular elements. Some preliminary qualitative tests showed in the latex, presence of certain enzymes and metabolic products like amino-acids, sugars, etc., showing thereby that latex does not only contain excretory products, but has also substances of some economic importance.
pp 107-115 August 1964
pp 116-127 August 1964
The rhizosphere of the Dolichos Enation Mosaic Virus-infectedDolichos lablab plants differed from that of the healthy plants. The effect of infection was reflected not only on the rate of accumulation of organisms in the rhizosphere, but also in the time of manifestation of maximum rhizosphere effect. These have been examined with reference to the intensity of host-parasite interaction as related to 3 phases of disease development. Both soil moisture content and season have been shown to affect the rhizosphere effect pattern of infected plants. That this is a result of altered host-parasite interaction is indicated.
pp 128-134 August 1964
pp 135-144 August 1964
The twinning laws and the composition of one hundred and ten plagioclase twin crystals from the anorthositic rocks of Oddanchatram, Madurai District, have been determined with the four-axes universal stage by the Reinhard’s method. The significance of the frequencies of different twinning laws in the plagioclases as well as the mineralogical and textural characteristics of the rocks in relation to their genesis are briefly discussed.
pp 145-154 August 1964
The results of experiments in connection with the estimation of nitrogen fixed by four species of blue-green algae are presented and discussed. The species tested wereTolypothrix campylonemoides, Nostoc sphaericum, N. amplissimum andWestiella sp. Of these,Tolypothrix was the most efficient. The quantity of extra-cellular nitrogen liberated has also been estimated; this is only a fraction of the whole. The potentialities of using blue-green algal species in rice culture are discussed. It is indicated that blue-green algae could be employed as a substitute for nitrogen fertilizers such as ammonium sulphate, for rice culture in waterlogged conditions.
pp 155-161 August 1964
The occurrence of manganese ore deposits of Eklingji, a locality situated about 14 miles NNE of Udaipur Town, is recorded here for the first time.
The country rocks in which the ores occur are Aravalli phyllite, quartzite and limestone striking NE-SW to N-S. Workable ores are generally found occupying the joints, bedding planes and brecciated portions of the country rocks. There are also some instances of concentration of ores in pockets and cavities within the host rocks.
Hard and massive ores are more common than soft and powdery ores. Generally the ores are found in botryoidal, mamillated and various other forms usually having colloform bandings. Ore-microscopic study of the ores revealed the presence of cryptomelane, manganite and pyrolusite. Often the ores have concentric or linear banded texture of colloidal origin. Crystalline pyrolusite (polianite) and manganite either occupy vugs and small cavities within colloform ores or are radially arranged on their surfaces. The paragenetic sequence of the ore-minerals has been suggested on the basis of their textural relationship. The origin of the ore-minerals has been attributed to solidification and crystallization of a colloidal manganese ‘gel’ that mineralised the country rocks along planes of weakness at a low temperature.