Volume 63, Issue 5
May 1966, pages 235-278
pp 235-238 May 1966
pp 239-246 May 1966
pp 247-250 May 1966
pp 251-257 May 1966
Tetraploid and hexaploid races were discovered inV. anagallis Linn. from Kashmir and Punjab plains respectively. There are significant morphological differences between the two races. A cytotaxonomic investigation was, therefore, undertaken.
Cytological studies reveal that the polyploid races are, in all probability alloploid in character. In view of their distinct morphological and cytological characteristics and geographical isolation, a consideration of the two races ofV. anagallis complex as two subspecies of the parent species, seems to be justified. However, before this is done, a comparison with the type material of the species needs to be undertaken.
The races are geographically isolated. The pattern of distribution is indicative of the fact that the tetraploid prefers colder and northern areas, while the hexaploid is adapted to warmer and southern areas.
pp 258-260 May 1966
1. Method for determining mitotic peak time inDraparnaldia plumosa (Vauch.) Ag. has been described.
2. Primary mitotic peak when there was 12 hours light followed by 12 hours darkness occurred two hours before the end of the light period (5% cells showed mitosis).
3. Secondary mitotic peak occurred one hour before the end of each of the two dark periods involved in the 36 hours.
4. The duration of mitosis in the alga was about 3 hours.
pp 261-270 May 1966
In the Jharia Coalfield, Bihar, dykes and sills of mica lamprophyre are common and have thermally metamorphosed the coal seams in contact into natural coke. Petrological study of the metamorphosed zones of the coal seams in the south-eastern extremity of the coalfield has been carried out. Four petrologically distinct zones designated as natural coke, coked coal, affected coal and unaffected coal are traced, when studied away from the contact. Chemically, a marked increase of volatiles and decrease of ash is recorded away from the seam-igneous contact. Phosphorus content is quite high in the natural coke ash.
The natural coke is characterised by numerous mineral-filled or empty vacuoles and strongly anisotropic, highly-reflecting nature of the fused matrix having physically unaltered fusinite embedded. The fused matrix is of mosaic appearance and consists of ill-defined units varying from one to fifty microns size. In the coked coal, the size and number of vacuoles has considerably reduced, and so also, the anisotropism and mosaic appearance of the matrix, accompanied by an increase in size of the units around fifty microns. The affected coal is distinctly folded, though minutely, and is micro-laminated, the lamination being due to occurrence of vitrinite layers and sheets with interbedaed fusinite, semifusinite, resinite and micrinite. The vesicles occur here and there. Resinite is seen in cleats and as coalesced films migrated along the bedding. The unaffected coal is a typical banded bituminous coal. The natural coke formation is discussed. Graphite is concluded to be absent.
pp 271-274 May 1966
Node is unilacunar inP. coronopus andP. pumila, trilacunar inP. ovata, and multilacunar inP. lagopus andP. major.
The number of leaf gaps directly varies with leaf size and its base.
pp 275-278 May 1966