Volume 9, Issue 2
February 1939, pages 63-116
pp 63-68 February 1939
pp 69-73 February 1939
It can be said that Actinomycetes do not show any periodic phenomenon such as we find in the other groups of soil organisms. The curve on Fig. 1 shows that the numbers of Actinomycetes seem to scatter about a mean value between four to eleven millions per gram of dry soil.
In the Punjab soils the numbers of Actinomycetes is slightly greater than those reported by the American and European workers.
pp 74-86 February 1939
The flowers examined are all carpellate ones, having about 15 stami-nodes which often show development up to the reduction division of the microspore-mother cells.
The study of vascular supply does not give any clue into the nature of the disc but it may be a luxuriant outgrowth of the torus.
The vascular supply presents evidence for the fact that the placental region of the ovary is formed by the fusion of only two margins of two different carpels, and not four as we should expect in axile placentation, and that the remaining two margins lie in the periphery and have become sterile, so that each carpel bears only one ovule.
Development of the embryo-sac proceeds after theNormal-type. It would be unfair to express my gratitude to my teacher, Dr. P. Maheshwari without adding that thanks to him must not be interpreted as an attempt to claim his support forall the statements made in the paper.
pp 87-98 February 1939
Tetrastichus sokolowskii is a parasite ofPlutella maculipennis. The wasp lays eggs inside the caterpillar which pupates the next day. The maximum number of eggs laid by a female was 127, the maximum number of parasites emerging from a single pupa was 25. Cases of parthenogenesis have been met with. The life-cycle of the parasite varied from 10–15 days. The maximum longevity was 34 days in the case of a female. The percentage of incidence of the wasp ranged from 18·2 to 68·5, the highest being in November.
pp 99-116 February 1939
In the present work the question of the position of the Magnoliales from the point of view of their epidermal features has been taken up. This is rather a new line of inquiry. Florin’s criteria,viz., the haplocheile and syndetocheile types of stomatal development have been made use of. According to this test the Magnoliales are seen to comprise a few synthetic forms, some possessing certain Cycadean features, the great majority the Bennetti-talean, and a few the haplocheile gymnosperm features.
The aberrant epidermal features ofEuptelea andCercidiphyllum seem to be correlated with other primitive features of Trochodendraceæ already known.
The view has again been expressed that the progenitors of the angio-sperms have to be sought for in that plexus of gymnosperms which gave rise to the Bennettitales, the syndetocheile Gnetales, the haplocheile Magnoliales and the majority of the Magnoliales(i.e., syndetocheile) along different lines of descent,the last being probably nearest related to the Bennettitales. From the point of view of epidermal studies, the Magnoliales do not represent a co-sanguinary group, but indicate a convergence.