EDITORIAL ADVISORY BOARD

R. MCN. ALEXANDER B. HEINRICH J. E. PHILLIPS

P. F. BAKER E. A. KRAVTTZ R. M. PITMAN

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B. M. H. BUSH S. H. P. MADDRELL S. E. REYNOLDS

P. J. BUTLER H. MARKL D. B. SATTELLE

J. C. ELLORY G. NEUWEILER K. SCHMIDT-NIELSEN

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© The Company of Biologists Limited 1984

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The Journal of

Experimental Biology

EDITED BY

J. E. TREHERNEWITH W. A. FOSTER & P. K. SCHOFIELD

VOLUME 1101984

THE COMPANY OF BIOLOGISTS LIMITEDCAMBRIDGE

Published by The Company of Biologists Limited, Department of ZoologjJUniversity of Cambridge, Downing Street, Cambridge CB2 3EJ

© The Company of Biologists Limited 1984

Typeset and Printed by the Pindar Group of Companies, Scarborough,North Yorkshire

CONTENTSPAGE

DAVIS, W. J., KOVAC, MARK P., CROLL, ROGER P. AND MATERA, EUGENE M. Brain

oscillator(s) underlying rhythmic cerebral and buccal motor output in the mollusc,Pleumbranchaea californica 1

FENCHEL, T . AND FINLAY, B. J. Geotaxis in the ciliated protozoon Loxodes. . . . 17

DOMINICK, OLIVER S. AND TRUMAN, JAMES W. The physiology of wandering

behaviour in Manduca sexta. I. Temporal organization and the influence of theinternal and external environments • 35

HOUSTON, A. H. AND KOSS, T . F. Plasma and red cell ionic composition in rainbowtrout exposed to progressive temperature increases 53

SPENCER, A. N. AND ARKETT, S. A. Radial symmetry and the organization of central

neurones in a hydrozoan jellyfish 69

FEDER, MARTIN E., SEALE, DIANE B., BORAAS, MARTIN E., WASSERSUG, RICHARD

J. AND GIBBS, ALLEN G. Functional conflicts between feeding and gas exchangein suspension-feeding tadpoles, Xenopus laevis 91

PACKARD, MARY J., PACKARD, GARY C. AND GUTZKE, WILLIAM H. N. Calcium

metabolism in embryos of the oviparous snake Coluber constrictor 99

HUEY, RAYMOND B. AND HERTZ, PAUL E. Effects of body size and slope on accelera-

tion of a lizard (Stellio stellio) 113

HARRIS, GERARD J. AND MORGAN, ELFED. The location of circa-tidal pacemakersin the estuarine amphipod Corophium volutator using a selective chillingtechnique 125

RIND, F. CLAIRE. A chemical synapse between two motion detecting neurones in thelocust brain 143

HENNESSEY, TODD M. AND KUNG, CHING. An anticalmodulin drug, W-7, inhibits thevoltage-dependent calcium current in Paramecium caudatum 169

FISH, F. E. Mechanics, power output and efficiency of the swimming muskrat(Ondatra zibethicus) 183

DEAN, JEFFREY AND WENDLER GERNOT. Stick insect locomotion on a wheel: patternsof stopping and starting 203

BATTY, R. S. Development of swimming movements and musculature of larvalherrings (Clupea harengus) 217

EVANS, PETER D. Studies on the mode of action of octopamine, 5-hydroxytryptamineand proctolin on a myogenic rhythm in the locust 231

YOKOTA, STANLEY D. Feeding and excretion in the scorpion Paruroctonus mesaensis:water and material balance 253

LILLYWHITE, HARVEY B. AND SMITS, ALLAN W. Lability of blood volume in snakesand its relation to activity and hypertension 267

)ONNELL, M. J. AND MADDRELL, S. H. P. Secretion by the Malpighian tubules ofRhodnius prvlixus Stal: electrical events 275

iv Contents

BOUTTLIER, ROBERT G. Characterization of the intermittent breathing pattern inXenopus laevts 291

LEECH, C. A. AND TREHERNE, J. E. Growth and ion-specificity of excitability inregenerating cockroach giant interneurones 311

SHORT COMMUNICATIONS

CRUSE, H. AND MOLLER, U. A new method measuring leg position of walking crus-taceans shows that motor output during return stroke depends upon load . . . 319

TRUEMAN, E. R., BONE, Q. AND BRACONNOT, J. C. Oxygen consumption in swim-ming salps (Tunicata: Thaliacea) 323

STEIN, P. G. AND ANDERSON, P. A. V. Maintenance of isolated smooth muscle cellsof the ctenophore Mnemiopsis 329