DEC i::^ 



New Series, No. 204 (Vol. 51, Part 4). Price lOs. net. 



Subscription per volume (of 4 parts) 40s. net. 

 NOVEMBER, 1907. 



THE 



QUARTERLY JOURNAL 



OF 



MICROSCOPICAL SCIENCE. 



EUlTEl) KY 



SiK EAY LANKESTER, K.C.B., M.A., D.Sc, LL.D., F.R.S., 



NOKARY 



KELLl 



OV VHt 



VCE 



UF EXETEll CUM. KGB, UXFuKD J COK II KSPUSDE S T UV THE INSTITIJTI 

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

 OF ^.SCIENCES OF PHILADELPHIA, ASD OP THE ROYAL ACADEMY OF SCIENCES 

 OF TURI.v; FOREIGN MEMBRK OP THE ROYAL SOCIETY OF SCIENCES OP 

 GOTTINGEN, AND OP THE ROYAL BOHEMIAN SOCIETY OF SCIENCES, AND 

 OP THE ACADEMY OP THE I.INCEI OP ROME. AND OF THE a:«EUICAN 

 ACADEMY OP ARTS AND SCIENCES OP BOSTON ; ASSOCIATE OP THE 

 ROYAL ACADEMY OP BELGIUM: HONIiRARY MEMBER HP THE 

 NEW YORK ACADEMY OF SCIENCES, AND OF THE 

 CAMBRIDGE PMILOSUP H ICAL SOCIETY, AND OF 

 THE ROYAL PHYSICAL SOCIETY OF EDIN- 

 BURGH, AND OP THE 

 BIOLOGICAL SOCIETY OF PARIS, AND OF THE CALIFORNIA ACADEMY OF SCIENCES OF SAN FRANCISCO; AND 

 OK THE ROYAL ZOOLOGICAL AND .MALACOLOGICA L SOCIETY OP BELGIUM; 

 CORRESPONDING MEMBER OF THE SENKENBERG ACADEMY OF FRAN KFURT-A-M ; 

 FOREIGN ASSOCIATE OP THE NATIONAL ACADEMY OF SCIENCES, U.S., AND MEMBER OP THE 

 AMERICAN PHILOSOPHICAL SOCIETY i 

 DIRECTOR OF THE NATURAL HISTORY DEPARTMENTS OF THE BRITISH MUSEUM! LATE PRESIDENT OP THE BRITISH 

 ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE,* LATE PULLKUIAN PROFESSOR OF 

 PHYSIOLOGY IN THE ROYAT. INSTITUTION OP GREAT BRITAIN ', 

 LATE LINACRE PROFESSOR OF COMPARATIVE ANATOMY AND FELLOW OF MERTON COLLEGE, OXFORD. 



WITH THE CO-OPERATION OF 



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



PROFESSOR OF ZOOLOGY AND COMPARATIVE ANATOMY IN THE UNIVERSITY OF CAMBRIDGE; 



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



BEYER PROFESSOR OP ZOOLOGY IN THE UNIVERSITY OF .MANCHESTER; 

 AND 



E. A. MINCHIN, M.A., 



PROFESSOR OF rROTOZOOLOGY IN THE UNIVERSITY OF LONDON. 



WITH LITHOGRAPHIC PLATES AND TEXT-FIGURES. 



LONDON : 



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



^^^ 1907. 



Adlard and Son, Impr.,] 



[London and Dorking. 



