Volume 84, Issue 5
November 1976, pages 155-199
pp 155-158 November 1976
The evaluation of fungicides including an antibiotic invitro indicated an apparent superiority of systemic fungicidesviz., Aureofungin, Plantvax and Vitavax over other types of fungicides tested. Among diticarbamates, Dithane M45 gave good control. A new organophosphatic fungicide, Kitazin was tested for its suitability and found 100% to give inhibition at 500 ppm and about 50% inhibition at 250 ppm.
pp 159-164 November 1976
pp 165-172 November 1976
Sexes could be distinguished inP. laevis on the basis of secondary sexual characters. Copulation occurred during spring and monsoon seasons. Fertilization was internal and the female carried the brood in a ventral brood pouch. Early period of life following emergence until completion of the third moult was most vulnerable and humidity played a critical role. During the life span of about 12–18 months, nine to ten moults occurred and with each moult there was an increase in body length.
pp 173-179 November 1976
In contrast to other Orchidaceae, the stomata inVanilla planifolia andV. wightii, are predominantly of the para-mesoperigenous type but the meristemoid is squarish as in other members of the family. 16% of the stomata inV. planifolia and the stomata on the scale-leaves ofV. wightii are of the aperigenous type; inV. planifolia, a few stomata (8%) are anisomesogenous (meristemoid triangular) and others (2%) hemipara-mesoperigenous. InV. wightii subsidiary cells of the para-mesoperigenous cauline stomata divide secondarily to form 5–7 subsidiary cells. Stomata are abundant on the stem ofV. wightii (stomatal index-3·4) but sparse inV. planifolia (index-0·57). There is a progressive increase in stomatal index from base to apex of the leaf ofV. planifolia. About 80% of the the stomata in mature leaves ofV. planifolia degenerate, as leaves get older. The epidermis is devoid of trichomes in both species. InV. planifolia, each epidermal cell has a large crystal included in it. It is suggested that the stomatal types inVanilla indicate the relationship of Orchidaceae to Hypoxidaceae, throughCurculigo, which also has para-mesoperigenous stomata.
pp 180-184 November 1976
Embryo sac development conforms to Polygonum type. Starch grains are noticed in the embryo sac right from the megaspore mother cell stage. Twin tetrads one with a chalazal functional megaspore and another with a micropylar functional megaspore have been noticed in some ovules. While 75% of the embryo sacs have normal polarity, in 20% of the ovules reverse polarity has been noticed. In the remaining 5% of the ovules, ‘bipolarity’ has been observed. Reverse polarity in relation to double archegoniate theory has been discussed.
pp 185-191 November 1976
Three new species of the genusSergiolus Simon are described and illustrated namelyS. poonaensis, S. meghalayensis, S. singhi.
pp 192-199 November 1976
A microphallid metacercaria resembling that ofMicrophallus nicolli (Spelotrema nicolli) Baer 1943, is reported from the sand crabs,Emerita asiatica andAlbunea symnista, on the Madras Coast and tentatively identified as belonging to the genusMicrophallus.
The larva is enclosed in a 3-layered spherical cyst, clothed with minute spines in the anterior two-thirds of the body, and shows short, blunt, postero-laterally directed intestinal crura, oval testes overlapped by large lobulated masses of vitellaria, a male genital papilla with no cuticular pockets, and a Y-shaped excretory vesicle.
High infection rates in the hosts were observed, all of 144E. asiatica (16–31 mm long) and 22 of 23A. symnista (13–27 mm long) examined between July and August 1974 having been infected in varying intensities. Strangely, only the female crabs harboured the metacercariae, in the connective tissue of the ovaries, the males being free. The ovary appeared to be the primary seat of infection, though parts of the liver may be involved. Neither the first intermediate host (gastropod), nor the definitive host (shore-birds ?) is yet known.