Volume 60, Issue 5
November 1964, pages 299-360
pp 299-303 November 1964
pp 304-308 November 1964
pp 309-314 November 1964
1. The morphology and life-history of a new haplosporidian parasite,Coelosporidium schmackeriae, from the body cavity of the copepodSchmackeria serricaudata is described.
2. The earliest stage observed was an amoebula which developed into multinucleate plasmodia.
3. The plasmodia may undergo a process of asexual multiplication or plasmotomy and this may be repeated.
4. Spore formation took pláce inside the plasmodia by the fragmentation of the cytoplasm into uninucleate bodies and these bodies ultimately developed into uninucelate simple spores enclosed in a common cyst.
5. Cysts are ovoid measuring 25·0µ in diameter and enclose 70–80 spores. The spore is ovoid measuring 3·0µ × 27sd5µ and provided with a rigid double envelope. Neither an operculum nor a bivalve nature of the spore was noticed.
6. The systematic position of the parasite is discussed.
pp 315-335 November 1964
pp 336-340 November 1964
“Purple Blotch” disease, which has recently been observed in Punjab, is caused byAlternaria porri (Ell.) Neergaard. It causes heavy damage to onion crop. Both the leaves and seed stalks are attacked. The symptoms of the disease under Punjab conditions have been described.
Pathogenicity to onion leaves, seed stalks and bulbs has been established. It has also been proved that fungus causing “Purple Blotch” of onion is a wound parasite and has got very limited host range.
pp 341-346 November 1964
Small lumps of crystalline magnetite occur as disseminated bodies within granite-pegmatite of Archean era in Hazaribagh District, Bihar. The following opaque minerals were identified by ore microscopic studies of the polished specimens of the ores: magnetite, hematite (primary), ilmenite, maghemite, martite, goethite and pyrite. Hematite and ilmenite show exsolution relation, whereas maghemite, martite, and goethite replace magnetite in different stages of oxidation.
The textural studies of the ore minerals indicate that magnetite is the earliest mineral formed, followed by the crystallisation of hematite-ilmenite intergrowth. Maghemite, martite and goethite are the altered products of magnetite and come later in the paragenetic history.
pp 347-350 November 1964
pp 351-360 November 1964
The unitegmic, tenuinucellate ovules ofPsychotria andRandia show after fertilization a massive chalazal growth which is more pronounced in the former than in the latter. InPsychotria, the epidermis forms deep or shallow infoldings into the inner layers that grow around the young, quiescent endosperm; the infoldings are confined to the chalazal part alone and are absent in the integumentary part. InRandia malabarica, the epidermis forms shallow and irregular undulations both in the chalazal and the integumentary parts.
The endosperm remains quiescent and of small volume during the early stages of seed development. When the seed has attained nearly its mature size, the endosperm grows rapidly in volume and attains a ruminate configuration by replacing all the surrounding tissues of the seed except the epidermis which, with its infoldings or undulations, serves as the mature seed coat.Psychotria shows a graded variation from a pronounced degree of rumination inP. congesta to complete absence of rumination inP. bisulcata, through a gradually decreasing series represented byP. dalzellii, P. elongata, P. reevesii, P. serpens andP. macrocarpa. The cell walls of the mature seed coat do not become thickened inPsychotria, but inRandia malabarica, they acquire an Ericaceous type of lignification.