New Series, No. 185 (Vol. 47, Part 1). 

 '^^^^ MAY, 1903. 



Price 10s. 



THE 



QUARTERLY JOURNAL 



OF 



MICROSCOPICAL SCIENCE. 



EDITED BY 



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



HONORARY FELLOW OK EXETER COLLEGE, OXFORD ; COB R ESPOMDEJJ T OF THE INSTITUTE OP PRANCE 



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 LINCEI OF ROME, 



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



ASSOCIATE OF THE ROYAL ACADEMY OP BELGIUM; HONORARY MEMBER 



UP 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 



OP Paris; 



DIRECTOR OP THE NATURAL HISTORY DEPARTMENTS OF THE BRITISH MUSEUM; LATE FUMiBRIAN 

 PROFBS30R OF FHYSIOI'OGY IN THE ROYAIi INSTITUTION OP GREAT BIVITAIN. 



WITH THE CO-OPERATION OP 



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



FELLOW AND TUTOR OF TRINITY COLLEGE, CAMBRIDGE; 



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



AND 



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



BEYER PROFESSOR OF ZOOLOGY IN THE OWENS COLLEGE, MANCHESTER. 



WITH LITHOGRAPHIC PLATES AND ENGRAVINGS ON WOOD, 



LONDON : 



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



1903. 



Adlard and Son,] 



[London and Dorkiufr. 



