Volume 58, Issue 6
December 1963, pages 325-385
pp 325-332 December 1963
The unitegmic, tenuinucellate ovules ofVoacanga grandifolia andErvatamia heyneana of the Apocynaceae show massive-chalazal growth after fertilization. The integumentary part of the ovule also grows to a certain extent. Due to differential growth activity of the inner layers and the epidermis, the latter forms infoldings into the former. The epidermal layer becomes thickened in a peculiar manner, but the inner layers remain thin-walled. The endosperm develops late and becomes ruminate by replacing all the inner layers of thin-walled cells and leaving intact the epidermis alone with its infoldings as the mature seed coat. Outgrowth from around the funicle forms a prominent aril inErvatamia heyneana and a common fleshy mass around the seeds inVoacanga grandifolia.
InTabernaemontana sp. chalazal growth is lesser, and even though the seed surface becomes irregular during early stages, the endosperm does not become ruminate.
pp 333-347 December 1963
pp 348-350 December 1963
Arthrobotryum coonoorense Subram. is considered to possess features warranting disposition in a separate genus. It is not congeneric withA. stilboideum Ces., the type species of the genus since the former produces dry phragmospores from conidiophores capable of repeated proliferation through areas of disjunction of spores and successive production of spores at progressively higher levels; in the latter the phragmospores are slimy and are produced from typical annellophores which are in the form of distinct sporogenous cells. Accordingly,Arthrobotryum coonoorense is made the type of a new genusAnnellophragmia and disposed asA. coonoorensis (Subram.) Subram.
I am grateful to the Rev. Fr. Dr. H. Santapau for very kindly translating into Latin the diagnosis of the new genus.
pp 351-361 December 1963
Twelve locally available species ofClerodendron have been examined for a comparative study of stone-cell structure, distribution and ontogeny. The species fall into two classes. First group includesC. fragrans, C. infortunatum, C. splendens andC. minahassae which have brachysclereids developed from transformed parenchyma cells of cortex or pith. The second group includesC. aculeatum andC. inerme which have “spheroidal sclereids” formed by the conversion of the collenchyma cell of the cortex. This has not been, as I am aware, reported so far. Both types develop by the “secondary sclerosis” of either the parenchyma cell or the collenchyma cell. So far as has been noticed, stone-cells seem to be present only in those species where the sclerenchyma or the phloem fibres are absent. It is therefore suggested that probably they both serve the same function of giving mechanical strength to the plant body. It has also been pointed out in view of the occurrence of some kind of crystals in these stone-cells, that they may be functioning as the repositories of excretory or secretory products.
pp 362-366 December 1963
This paper records with brief notes new records and localities for the occurrence of the following flowering plants from Saurashtra coast and neighbouring islands:Merremia quinquefolia (L.) Hall. f.,Euphorbia heterophylla L.,Kedrostis rostrata (Rottl.) Cogn.,Portulaca tuberosa Roxb.,Grewia villosa Willd.,Alhagi pseudalhagi (M. Bieb.) Desv.,Delonix elata (L.) Gamble,Psilostachys sericea (Koen. ex Roxb.) Hook. f.,Maerua arenaria Hook. f. and Thoms. var.scabra Hook. f. and Thoms.,Vogelia indica Gibs. ex Wight,Solanum dubium Fresen,Solanum arundo Mattei andPavonia patens (Andr.) Chiov.
pp 367-374 December 1963
The effect of injection of insulin intoMeretrix casta has been investigated. Insulin lowers the blood glucose level significantly after an hour following the injection; recovery sets in later. Increase of dosage of insulin produces increased lowering of blood glucose.
Injection of insulin produces an increase of glycogen content in the digestive diverticula and foot but there is a differential effect of insulin on the glycogen content of digestive diverticula and foot. The former seems to be a labile storehouse of carbohydrates and the latter a more stable store, with probably some mechanism of regulation.
pp 375-385 December 1963
The paper reports on an embryological investigation ofChaenorrhinum minus. The development of the female gametophyte is of the Polygonum type. The antipodal cells degenerate early. The endosperm isab initio cellular. The chalazal haustorium is unicellular and binucleate, although occasionally a uninucleate state occurs. No micropylar haustorium is organized. The persistent, thick-walled endothelial cells contribute to the 4–5-layered seed coat. The findings have been evaluated in the light of previous work on the tribe Antirrhineae.