Volume 73, Issue 5
May 1971, pages 209-263
pp 209-220 May 1971
(1) Toxicity of three fumigants is in the order trichloro-ethylene > EDCT > 1, 2, dibromo-3-chloropropane.
(2) Toxicity to the insects investigated was directly related to the amount of carbon dioxide produced during fumigation.
(3) A high percentage of spiracular openings per minute is necessary for high toxicity.
(4) Penetration of three fumigants through integument was in the order trichloroethylene > 1, 2, dibromo-3-chloropropane > EDCT.
(5) Spiracular action during fumigation plays an important role for the entry of gases.
pp 221-223 May 1971
A mutant for high ginning out-turn has been induced by X-rays in a Cambodia cotton. The fibre qualities of this mutant are reported.
pp 224-235 May 1971
The House-swift (Apus affinis affinis, J. E. Gray) is a very rapid flier and it hawks high in the air for its food which normally comprises small insects such as mosquitoes and other dipterans. During their flight they keep their mouth open and it is closed when the prey comes in contact with the bill. A study of the functional anatomy of the feeding apparatus in this bird was undertaken to find out the adaptations which pertain to the epidermal structures of the bill, shape of the tongue, skull architecture and the cranial musculature operating the bill. Emphasis is laid on the musculature of the bill and tongue in light of the functions performed.
pp 236-240 May 1971
The crabParatelphusa masoniana (Henderson) is commonly found in the local waters. It has a slightly advanced type of vascular system as compared to other crustaceans. The heart of the animal has been subjected to the effect of common drugs and antibiotics. The observations indicate that the drugs like adrenalin, camphor and digitalin stimulate the heart, while aspirin, atropine, caffein, chloroform, ether, strychnin and arsenite inhibited the heart-beats. Similarly, except the combiotic all other antibiotics affected the heart of the crab adversely.
pp 241-250 May 1971
The ovary is usually tricarpellary, rarely bicarpellary and covered with spines and glandular and eglandular hairs inMarah macrocarpa Greene. Structure and development of spines and two types of hairs are described. Ovules are anatropous, bitegmic and crassinucellate. The ovular bundle ramifies after fertilization. Development of embryosac is of Polygonum type. The pollen-tube is persistent and sometimes dilates at the base of the nucellar beak. The endosperm is Nuclear and enucleate cytoplasmic nodules are formed. The wall formation is progressive and chalazal endosperm haustorium is short and coenocytic. Rarely, it is rudimentary. Embroyogeny is suggestive of Onagrad type. Hemitriand hemitetracotyledonary embryos are also recorded.
The seedcoat develops from the outer integument alone. The mature seedcoat comprises seed epidermis, hypodermis, main sclerenchymatous layer of narrow osteosclereids, (all derived from the outer epidermis of outer integument) aerenchyma and chlorenchyma.
pp 251-263 May 1971
Climatic conditions of Jorhat, a high percentage of relative humidity and low termperature during January, February are highly favourable for the infection and yield of ergot at Jorhat. The best time of sowing rye is the first fortnight of October and artificial infection during January. Out of 15 strains ofClaviceps purpurea used in this study, the “ergometrine” strain and “ergotamine” strain, received from the University of Johannes, Gutenberg, Mainz, performed most efficiently under the condition at Jorhat, giving high yields of sclerotia and alkajoids. The sclerotia produced by these strains were also larger in size than the average.
Artificial infection with spore suspension in cane-sugar (4·5%) produced higher yields of sclerotia of larger size as compared with artificial infection with spore suspension in water. A method for the extraction of ergotamine and ergometrine from the sclerotia is described. Following this method of extraction, the yield of ergometrine and ergotamine obtained could be favourably compared with the yields reported by other workers. Good prospect of large-scale cultivation of ergot under the climatic conditions of Jorhat and extraction of alkaloids is indicated by the study.