^- 



New Series, No. 201 (Vol. 51, Part 1). Price lOs. net. 



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

 FEBRUARY, 1907. 



THE 



QUARTERLY JOURNAL 



OF 



MICROSCOPICAL SCIENCE. 



EDITED BY 



E. EAY LANKESTER, M.A., D.Sc, LL.D., F.R.S., 



HONORAKY FELLOW OK KXETEIl COLLKGE, OXHOUl) ; C O R U ES P O N D BN T OI' THE INSTITUTE OK KKANCE 

 AND OF THE IMPERIAL ACADEMY OF SCIENCES OK ST. PETKUSBURG, AND OF TUE ACADEMY 

 OF SCIENCES OF PHILADELPHIA, AND OF THE ROYAL ACADEMY OF SCIENCES 

 OF TURIN ; FOREIGN MEMBRR OF THE ROYAL SOCIETY OF SCIENCES OF 

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

 OF TUK ACADEMY OF THE LINCEI OF HOME, AND QF THB AMERICA.V 

 ACADEMY OF ARTS AND SCIENCES OF BOSTON ; ASSOCIATE OK TUE 

 ROYAL ACADEMY OF BELGIUM; UONtiRARY MEMBER "F THE 

 NEW YORK ACADEMY OF SCIENCES, AND OF THE 

 CAMBRIDGE P U ILOS OF U IC AL SOCIETY, AND OP 

 THE ROYAL PHYSICAL SOCIETY OK EDIN- 

 BURGH, AND OF TUE 

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

 FOREIGN ASSOCIATE OF TUK NATIONAL ACADEMY OF SCIENCES, U.S ., AND MEMBER OK 

 THE AMERICAN P UILOSOP HICAL SOCIETY ; 

 DIRRCTOR OF TUE NATURAL HISTORY DEPARTMENTS OF TUE BRITISH MUSEUM; PRESIDENT OF TUE BRITISH 

 ASSOCIATION FOR THE ADVANCEMENT OF SCIENCR," LATE FULLKRIAN FROFRBBOR OF 

 PHYSIOLOGY IN THE ROYAL INSTITUTION OF 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., 



FEM.OW AND TUTOR 07 TRINITY COLLEGE, CAMBRIDGE; 



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



BEYER PROFKSSOB OF ZOOLOGY IN TUE OWEXS COLLEGE, MANC HESTK R ; 



AND 



E. A. MINCHIN, M.A., 



PROFESSOR OF rROTOZOOLOGY IN THE UNIVERSITY OF LONDON. 



WITH LITHOGRAPHIC PLATES AND TEXT-FIGURES. 



^ LONDON : 

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



1907. 



Adlard and Son, Impi-.,] 



[London and Dorking. 



