QUARTERLY JOURNAL t 



MICROSCOPICAL SCIENCE. 



EDITED BY 



E. RAY LANKESTER, M.A., LL.D., F.R.S., 



>XORARY FKI.LOW OF EXETER COLLEGE, OXFORD ; COR RF.SPON D KN T OK THE INSTITUTE OF FHANCE 



AND OF THE IMPERIAL ACADEMY OF SCIENCES OF ST. PETERSBURG, AND OF THE ACADEMY 



OF SCIENCES OF PHILADELPHIA; FOREIGN MEMBER OF THE ROYAL BOHEMIAN 



SOCIETY OF SCIENCES, AND OF THE ACADEMY OF THE LIXCEI OF ROMK« 



AND OF THE AMERICAN ACADEMY OF ARTS AND SCIENCES OF BOSTON ; 



ASSOCIATE OF THE ROYAL ACADEMY OF BELGIUM; HONORARY MEMBER 



OF THE NEW YORK ACADEMY OF SCIENCES, AND OF THE 



CAMBRIDGE PHILOSOPHICAL SOCIETY, AND OF THE ROYAL 



PHYSICAL SOCIETY OF EDINBURGH ; HONORARY 



MEMBER OF THE BIOLOGICAL SOCIETY 



OF PARIS; 



DIRKCTOn OF THE NATURAL HISTORY DEPARTMENTS OF THE BRITISH MUSEUM; LATE FULLRRIAN 



PROFESSOR OF PHYSIOLOGY IN THE ROYAL INSTITUTION OF GBEAT BRITAIN. 



WITH THE CO-OPERATION OF 



ADAM SEDGWICK, M.A., F.R.S., 



FELLOW AND TUTOR OF TRINITY COLLEGE, CAMBRIDGE; 



W. F. R. WELDON, M.A., F.R.S., 



LIN ACRE PROFESSOR OF COMPARATIVE ANATOMY AND FELLOW OF MERTON COLLEGE, OXFORD: 

 LATE FELLOW OF ST. JOHN's COLLEGE, CAMBRIDGE; 



SYDNEY J. HICKSON, M.A., F.R.S., 



BEYER PROFESSOR OF ZOOLOGY IN THE OWENS COLLEGE, MANCHKiiTER. 



VOLUME 46.— New Series. 



i 



LONDON: 



J. & A. CHURCHILL, 7, GREAT MARLBOROUGH STREET. 



1903. 



