New Series, No. 234 (Vol. 59, Part 2). Price 10s, net. 
Subscription per volume (of 4 parts) 40s. net. 
JULY, 1913. 
THE 
QUAUTERLY JOURNAL 
OF 
MICllOSCOPICAL SCIENCE. 
EDITKI) HY 
Sir KAY LANKESTER, K.C.B., M.A., D.Sc., LL.l)., P.R.S., 
ONOIIA KY FEM.OW 
MEMBEU OF TUK 
C O H It R a r O N 1) K N 
ACAD KM Y OK 
OP E.XKTKR COl.bKGR AND HONORARY STUDRNT OF CHRIST CHURCH, OXFORD; 
iNsniuTK OK kkanck (associ^ Stranger de i/acade.mie des sciences) ; 
' OP THK IMFKUIAI. ACADEMY OP SCIENCES OP ST. PETERSBURG, AND OP THE 
SCIENCES OP PHII.ADKI.PIIIA, AND OP THK ROYAL ACADEMY OF SCIENCES 
OP Turin; pokkign memurr op the royal society op sciences op 
GOTTINGEN, AND OF THE ROYAL BOHEMIAN SOCIETY OP SCIENCES, AND 
OP THK ACADEMY OP THE I.INCKI OP ROME, AND OP THK AMERICAN 
ACADEMY OF ARTS AND SCIENCES OF BOSTON; ASSOCIATE OP THK 
ROYAI. ACADEMY OF BELGIUM; HONORARY MEMBER OP THK 
NEW YORK ACADEMY OP SCIKNCES, AND OP TlIK 
CAMBRIDGE PHILOSOPHICAL SOCIETY, AND OP 
THE ROYAL PHYSICAL SOCIETY OP EDIN- 
BURGH, AND OF T H B 
BIOLOGICAL SOCIETY OP PARIS, AND OF THK CAI.IFORNIA ACADEMY OF SCIENCES OF SAN FRANCISCO, AND 
OF THK ROYAL ZOOLOGICAL AND M A L ACOLO GIC A L SOCIETY OP BELGIUM; 
CORRESPONDING MEMBER OF THE SENKKNBERG ACADEMY OF F R A N K F U RT- A' M ; 
FOREIGN ASSOCIATE OF THK NATIONAL ACADEMY OK SCIKNCES. U-S., AND MEMBER OF THE 
AMERICAN PHILOSOPHICAL SOCIETY ; 
HONORARY FELLOW OF THE ROYAI. SOCIETY OK EDINBURGH, 
LATK OlRKCTOIt OP THE NATURAL HISTORY DEPAKT.MKNTS OF THK BRITISH MUSKUM; LATE PRESIDENT OF THE 
BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE,' LATK PULLKKIAN PROFESSOR OF 
PHYSIOLOGY IN THK ROYAL INSTITUTION OF GRKAT BRITAIN , 
LATK I.INACKR PROFESSOR OF COMPARATIVE ANATOMY AND KELI.OW OF MERTON C O M.F G K , O X FO R D ; 
EMERITUS PROFESSOR OF ZOOI.OGY AND COMPARATIVE ANATOMY IN UNIVERSITY COLLEGE, UNIVERSITY OF LONDON. 
WITH THE CO-OPERATION OF 
SYDNEY J. HICKSON, M.A., F.R.S., 
BEYER PROFESSOR OP ZOOLOGY IN THK UNIVERSITY OF MANCHESTER; 
E. A. MINCHIN, M.A., F.R.S., 
PHOKKSSOR OF PROTOZOOLOGY IN THE UNIVERSITY OP LONDON; 
GILBERT C. BOURNE, M.A., D.Sc., E.R.S., 
I.INaCRE FKOFKSSOR of CO.MPARATIVE anatomy, and FKM.OW of MKRTON COI.r.EGK, OXFORD 
AND 
J. GRAHAM KERR, M.A., F.R.S., 
REGIUS PROFESSOR OF ZOOI.OGY IN THE UNIVERSITY OF GLASGOW. 
WITH LITHOGRAPHIC PLATES AND TEXT-FIGURES. 
J. & A. CHURCHILL, 
LONDON. 
7 GREAT MARLBOROUGH STREET. 
1913. 
Adlard and Son^ Impr.,] 
-[London and Dorking. 
