ny'^/ti^Hu./^ -^ 



New Series, No. 219 (Vol. 55, Part 3). Price lOs. net. 



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

 SEPTEMBER, 1910. 



THE 



QUARTERLY JOURNAL 



OF 



MICROSCOPICAL SCIENCE. 



EDITED BY 



Sir ray LANKESTER, K.C.B., M.A., D.Sc, LL.D., F.R.S., 



HunoilAlvY KKI.I.OW OK EXKTEK COl.l.KGE, OXI'OKl) ; 

 MEMBEll or TUE INSTITUTE OK K 11 A N C E {aSSOCi£ fcilRANGEB UE l'aCADEMIE DES SCIENCES) ; 

 COUUKSPONLKNT OF TUK IMPEIllAI. ACADEMY OK SCIEftCEa OK ST. PETKU8BUUG, A IS D OK TUK 

 ACADKMY OF 8CIENCK3 OK PHILADELPHIA, AND OK THE ROYAL ACADEMY OK SCIKNCES 

 OK TURIN; FOIIEIGN MEMBER OF TUE ROYAL SOCIETY OF SCIENCES OF 

 GOTTINGEN, AND OF TUE KOYAL BOHEMIAN SOCIETY OK SCIENCES, AND 

 OF TUK ACADEMY OF THE LINCEI OF ROME, AND OK THE AMERICAN 

 ACADEMY OK ARTS AND SCIENCES OK BOSTON", ASSOCIATE OK TUB 

 ROYAL ACADEMY OF BELGIUM; HONOKARY MEMBER OF THE 

 NEW YORK ACADEMY OP SCIENCES, AND OF TUB 

 CAMBRIDGE PUILOSOPHICAL SOCIETY, AND OP 

 THE ROYAL PHYSICAL SOCIETY OK EDIN- 

 BURGH, AND OF TUB 

 BIOLOGICAL SOCIETY OF PARIS. AND OF THE CALIFORNIA ACADEMY OF SCIENCE.^ OK SAN FRANCISCO, AND 

 OF THE ROYAL ZOOLOGICAL AND MAL ACOLO GlC A L SOCIETY OF BELGIUM; 

 CORRESPONDING MEMBER OF THE SENKENBERG ACADEMY OF FR AN KFURT-A-M ; 

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

 AMERICAN PHILOSOPHICAL SOCIETY ; 

 HONORARY FELLOW OF THE ROYAL SOCIETY OF EDINBURGH; 

 LATE DIRKCTOH OK THE NATURAL HISTORY DEPARTMENTS OF THE BRITISH MUSEUM; LATE PRESIDENT OF THE 

 BRITISH ASSOCIATION K O K THE ADVANCEMENT OF SCIENCE; LATE FULI.KKIACn PKOFRS80R OK 

 PnYSIOL(JGY IN THE ROYAL INSTITUTION OF GREAT BRITAIN. 

 LATE I.INACRE PROFF.S80R OF COMPARATIVE ANATOMY AND FELLOW OF MKBTON C O I.l.E GE , OX FO R D ; 

 EMERITUS PROFESSOR OF ZOOLOGY AND COMPARATIVE ANATOMY IN UNIVERSITY COLLEGE, UNIVERSITY OF LONDON. 



WITH THE CO-OPEllATION OF 



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



FELLOW OK TRINITY COLLEGE, CAMBRIDGE. AND PROKE5SOR OF ZOOLOGY IN TUE IMPERIAL COLLEGE OK 



SCIENCE AND TECHNOLOGY, LONDON; 



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



BEYER PROKKBSOlt OF ZOOLOGY IN THE UNIVERSITY OF MANCHESTER; 



E. A. MINCHIN, M.A., 



FR<»FESSOR OF PROTOZOOLOGY IN THE UNIVERSITY OK LONDON; 



AND 



GILBERT C. BOURNE, M.A., D.Sc, F.R.S., 



I.INACRE PUOFKSSOU OF COMPARATIVR AKATOHY, AND FKI.I.OW OF MERTON COLLF.GK, OXFORD. 



WITH LITHOGRAPHIC PLATES AND TEXT-FIGUEES. 



LONDON. 

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



1910. 



4i 



Adlard and Son, Impr.,] 



[London and Dorking. 



