Volume 73, Issue 2
February 1971, pages 51-104
pp 51-52 February 1971
pp 53-57 February 1971
The paper reports the occurrence of two species of marine interstitial tardigrades,Stygarctus bradypus Schulz andBatillipes carnonensis Fize, from Indian waters. The morphological variations of the Indian forms differing from the European species are given, along with some ecological notes.
pp 58-64 February 1971
1. The morphology of the visceral arterial system of two teleostean fishes has been described.
2. InClarias batrachus the dorsal aorta is formed by the union of one pair of epibranchial arteries and supplies to the kidney, segmental muscles and body wall.
3. The coeliaco mesenteric artery supplies to the digestive tract and associated glands, air-bladder, pectoral girdles and mesentery. The posterior mesenteric artery also supplies to kidneys and reproductive organs.
4. InTor tor the dorsal aorta is formed by the union of two pairs of epibranchial arteries and supplies to the pectoral girdles, kidneys, segmental muscles and body wall.
5. The coeliaco-mesenteric artery supplies to whole of the digestive system and associated glands, air-bladder mesentery and reproductive organs.
pp 65-73 February 1971
The floral morphology of 9 species of Scrophulariaceae belonging to 5 genera included in 3 tribes is studied.
The floral anatomy suggests that the condition with four stamens is resulted from a five-stamened condition by a gradual reduction of posterior stamen.
The placentation inAntirrhinum, Nemesia andLinaria is axile. But in the basal region of the ovary ofScrophularia andVerbascum though the placentation is apparently axile it is anatomically parietal. In these members, however, the placentation is parietal in every way at the upper region of the ovary.
pp 74-77 February 1971
A new species of free-living freshwater hymenostomatous ciliate belonging to the genusDisemastoma Lauterborn collected from a pond in West Bengal, India, is described in this paper. It differs from the six known species of the genus in having a comparatively big horse-shoe-shaped macronucleus with slightly swollen ends located dorsally around the peristome. This is the first record of the genusDisemastoma Lauterborn in the Indian sub-continent and the nameDisemastoma bengalensis is suggested for the new species.
pp 78-83 February 1971
Neascus channi andN. xenentodoni are described from the Cranium of freshwater fishesChanna punctatus (Bloch) andXenentodon cancila (Hamilton) respectively. The former is characterised by ratio of its suckers, position of ventral sucker, pattern of reserve excretory system and by absence of a cyst while the latter chiefly differs from all the known species ofNeascus by ratio of fore-and hind-body, by ratio of suckers and by presence of a cyst.
pp 84-95 February 1971
Investigations carried out on the relationship of Bittergourd Mosaic virus and its vectors indicated that the pre-acquisition fasting threshold, acquisition threshold and inoculation feeding threshold were 15 minutes, 5 seconds and 60 seconds respectively forMyzus persicae; 15 minutes, 20 seconds and 5 minutes respectively forAphis gossypii; 30 minutes 30 seconds and 5 minutes respectively forAphis nerii andBrevicoryne brassicae; 30 minutes, 20 seconds and 5 minutes respectively forA. malvae. The optimum number of viruliferous aphids per plant for transmission was 15 for all the five aphid vectors; increasing the number of aphids above the optimum decreased the percentage of transmission. Persistence of the virus during fasting was 4 hours, 90, 60, 45 and 30 minutes respectively forM. persicae, A. gossypii, A. malvae, B. brassicae andA. nerii while persistence during feeding was 40, 30, 20, 15 and 10 minutes respectively for the same aphid vectors. Though both alate and apterous forms of the vectors transmitted the virus, the apterous forms were more efficient than the alate ones.
pp 96-104 February 1971
InAneilema paniculatum the endosperm is of the nuclear type. Compound starch grains are abundant in all cells except in the outermost layer.
The embryogeny is of the Asterad type and is placed under Commelina variation. A single instance of polyembryony has been observed.
The seeds are pale brown, irregular and hard. The seed is divided into a narrow micropylar collar region and the broad basal region. The former is occupied by the embryo and the latter, by the endosperm. The nucellus is represented by a thin band of degenerated cells.
The seed coat is formed from both layers of the inner integument and inner epidermis of the outer integument.