• Volume 72, Issue 5

      November 1970,   pages  187-240

    • Some observations on the branchiocephalic arterial system of teleosts

      O B Goswami S P Jain S S Khanna

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      1. The morphology of the branchiocephalic arterial system of two teleostean fishes has been described.

      2. InClarias batrachus, the short ventral aorta gives off four pairs of afferent branchial arteries, the second and fourth supplying to the abrorescent organs. A recurrent artery has been noted in each gill arch.

      3. The efferent branchials are paired within and uniting above the gill arches. The first and second efferent branchial arteries join to form the epibranchial arteries on each side, which again unite to form dorsal aorta. Arborescent organs pour into second and fourth pair of efferent branchial arteries.

      4. External and internal carotid supply the cephalic region, the cerebral arteries initiating the formation of circulus cephalicus.

      5. InTor tor four pairs of efferent branchial arteries spring from ventral aorta. The two epibranchials are formed on each side by the union of first and second; and third and fourth efferent branchial arteries respectively. These join in pairs one after the other and unite to form the dorsal aorta.

      6. The cephalic region is supplied by external and internal carotids, the latter forming the circulus cephalicus.

    • Studies on the visceral venous system of some Teleosts

      O B Goswami S P Jain S S Khanna

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      1. The morphology of the visceral venous system of two Teleostean fishes has been described.

      2. InClarias batrachus, the posterior cardinals are paired—the right larger than the left and both open into the ducti cuveri after receiving subclavian veins of their respective side.

      3. The caudal vein proceeds anteriorly receiving veins from body wall, segmental muscles, kidney and gonads and finally merges into the rectal vein.

      4. The hepatic portal system collects the blood from digestive tract and associated glands, mesentery, air-bladder pectoral girdles and posterior mesenteric system and pours it into the liver. From the liver a median hepatic vein joins the sinus venosus.

      5. InTor tor, a single posterior cardinal vein pours the blood into the ductus cuveri. The caudal vein proceeds anteriorly, supplies to the kidney and merges into it.

      6. The hepatic portal system collects the blood from entire digestive system and associated glands, reproductive organs, mesentery and air-bladder and pours it into the liver. From the liver paired hepatic veins join the ducti curveri.

    • Taxonomic status and identity ofCorvina albida Cuvier, 1830 (Pisces: Sciaenidae)

      P K Talwar

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      Considerable uncertainty exists about the taxonomic status and identity ofCorvina albida Cuvier, 1830 in view of the controversy regarding the presence or absence of mandibular barbels in this sciaenid.

      From a study of several specimens including Day’s (1876) figured examples and topotypes of this species and the types ofDendrophysa hoogliensis Sinha and Rao, 1969, it has been concluded that these two species are conspecific andDendrophysa albida (Cuvier) is a species with a pair of mandibular barbels.

    • Embryological studies in Capparidaceae - I. Sporogeneses and the development of gametophytes inCleome viscosa Linn

      Tasneem Fathima P Kusuma Kumari

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      Microsporogenesis, development of male gametophyte, megasporogenesis and the development of the female gametophyte inCleome viscosa Linn. have been described.

      The archesporium in the anther develops as a plate of three to four hypodermal cells. The anther wall is composed of epidermis, fibrillar endothecium, two middle layers and glandular tapetum. The tapetal cells become multinucleate. The endothecial thickenings extend on all the cells of the anther except the epidermis and the vascular strand. The epidermis becomes discontinuous and wavy. The microspore tetrads are of decussate and tetrahedral type. The pollen grains are shed at the three-celled stage. A stomium is organised during dehiscence.

      The ovules are campylotropous, bitegminal and crassinucellar. The archesporium is hypodermal and cuts off a parietal cell. The megaspore tetrad is linear. The chalazal megaspore is functional but occasionally the third megaspore in the tetrad functions further and the others degenerate. The development of the female gametophyte corresponds to the monosporic, Polygonum type. The synergids are hooked. The embryo sac is filled with starch grains.

    • Studies on the cephalochordates of madras coast - VI. Observations on the pharyngeal feeding mechanism in amphioxusBranchiostoma lanceolatum

      Jayapaul Azariah

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      The U-shaped endostyle of Amphioxus is known to secrete mucus. When the endostyle is separated from the two sides of the pharyngeal wall, the secreted mucus travels backwards along the groove without being lifted up. However, in an intact specimen the mucus is lifted up along the sides of the gill bar and spreads over the pharyngeal epithelium. As the mucus travels vertically upwards it acts as a moving “fly paper” to gather particles brought in by the water current.

      A feature of interest is the observation that the secretion of mucus is enhanced when the concentration of suspended particulate matter is increased. Such copious mucus production helps the formation of mucous sheets between the gill bars causing a reduction of gill slit area available for the outflow of water. In such cases the beating of cilia is masked and the ciliary beat could clearly be seen when the mucous sheets are being torn. It has been suggested that the mucus plays an important role in regulating the volume of water filtered besides the ciliary activity which is said to be under nervous control.

    • Contribution to the embryology ofLindernia hyssopioides (L.) Haines

      Govindappa D Arekal S Girijamma S N R Swamy

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      The results of an embryological investigation ofLindernia hyssopioides (L.) Haines [=Ilysanthes hyssopioides] (L.) Benth.] have been presented.

      The young anther wall consists of three layers of cells in addition to the glandular tapetum. The tapetal cells become binucleate and the nuclei fuse together. The endothecium acquires fibrous thickenings in later stages and the middle layer disorganizes. Quadripartition of microspore mother cells is simultaneous. The pollen grains at shedding are two-celled and tricolpate.

      The ovules on the massive axile placenta of the superior bicarpellary syncarpous ovary are anatropous, unitegmic and tenuinucellate. The development of the embryo-sac conforms to the Polygonum type. The two synergids are posteriorly vacuolate and have tapering anterior ends. The antipodal cells are ephemeral.

      The endosperm isab initio cellular. The division of the primary micropylar endosperm chamber is vertical and not transverse. The chalazal haustorium consists of two uninucleate cells. Occasionally it becomes 3-celled. The micropylar haustorium is made up of 4 uninucleate cells. The haustorial cells neither develop lateral extensions nor fuse together during seed development.

      The development of the embryo is of the Crucifer type. The daughter cell ofd functions as the hypophysis.

      The seeds are albuminous. The remains of the endothelium and the outer epidermis of the integument constitute the seedcoat.

      The results obtained have been evaluated in the light of earlier work in the tribe Gratiolae.

    • Nodulation of soybean as influenced by the liquid endosperm of coconut

      V Iswaran N P Jayasanker K S Jauhri N S Subba-Rao

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      The liquid endosperm of coconut showed a stimulatory effect on the number and volume of nodules of soybean (var. Bragg) inoculated with peat based culture ofRhizobium japonicum S.B. 16. Coconut water stimulated the growths ofRhizopus arrhizus on nodules which, in its turn, was shown to increase the growth ofR. japonicum.

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