7 5 ' A 7 
New Series, No. 247 (Vol. 62, Part 3). Price 10s. 6d. net 
Subscription per volume (of 4 parts) 42s. net. 
AUGUST, 1917 
THE 
QUARTERLY JOURNAL 
OF 
MICROSCOPICAL SCIENCE. 
EDITED HY 
Sie RAY LANKESTER, K.C.B., M.A., D.Sc., LL.D., F.R.S., 
HONOHAHT FELLOW OP EXETER COLLEGE AND HONORARY STUDENT OF CHRIST CHURCH, OXFORD ; 
MEMBER OP THE INSTITUTE OP PRANCE (ASSOClfc ETRANGER DE l/ACADEMIE DES SCIENCES); 
CORRESPONDENT OF THE IMPERIAL ACADEMY OP SCIENCES OP ST. PETERSBURG, AND OF THE 
ACADEMY OF SCIENCES OF PHILADELPHIA, AND OF THE ROYAL ACADEMY OF SCIENCES 
of turin; foreign member op tub royal society of sciences op 
GOTTINGEN, AND OF THE ROYAL BOHEMIAN SOCIETY OF 8CIENCE8, AND 
OF THE ACADEMY OP THE J.INCEI OF ROME, AND OF THE AMERICAN 
ACADEMY OF A R T 8 AND SCIENCES OF BOSTON 5 ASSOCIATE OF THE 
ROYAL ACADEMY OF BELGIUM; HONORARY MEMBER OF THE 
NEW YORK ACADEMY OF 8CIKNCRS, AND OF THE 
CAMBRIDGE PHILOSOPHICAL SOCIETY, AND OP 
THE ROYAL PHYSICAL SOCIETY OF EDIN 
BURG d, AND OF THE 
BIOLOGICAL AND ZOOLOGICAL SOCIETIES OF PARIS, AND OF THE CALIFORNIA ACADEMY OF SCIENCES OF 
SAN FRANCISCO, AND OP THE ROYAL ZOOLOGICAL AND M ALACOLOGIC AL SOCIETY OF BELGIUM; 
CORRESPONDING MEMBER OF THE 8ENKENBERG ACADEMY OF FRANKFURT A M J 
FOREIGN A 88 OCIATK OF THE NATIONAL ACADEMY OF 8CIBNCES. U-8., AND MEMBER OF THE 
AMERICAN PHILOSOPHICAL 80CIETY ; 
HONORARY FELLOW OF THE ROYAL SOCIETY OF EDINBURGH*, 
LATE DIRECTOR OF THE NATURAL HISTORY DEPARTMENTS OF THE BRITISH MUBRUM; LATE PRESIDENT OF THB 
BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE; LATE FULI.KRIAN PROFB 88 OR OF 
PHYSIOLOGY IN THE ROYAL INSTITUTION OF GREAT BRITAIN ; 
LATE LIN AC R K PROFK880R OF COMPARATIVE ANATOMY AND FELLOW OF MERTON C O LLE G R , O X F O R D ; 
EMERITUS PROFESSOR OF ZOOLOGY AND COMPARATIVE ANATOMY IN UNIVER8ITY COLLEGE, UNIVERSITY OF LONDON 
WITH THE CO-OPERATION OF 
SYDNEY J. HICKSON, M.A., F.R.S., 
BEYER PROFESSOR OF ZOOLOGY IN THE UNIVERSITY OF MANCHESTER; 
GILBERT C. BOURNE, M.A., D.Sc., F.R.S., 
LINACRE PROFESSOR OF COMPARATIVE ANATOMY, AND FELLOW OF MERTON COLLEGE, OXFORD 
J. GRAHAM KERR, M.A., F.R.S., 
REGIUS PROFESSOR OF ZOOI.OGT IN THE UNIVERSITY OF GLASGOW ; 
AND 
E. W. MACBRIDE, M.A., D.Sc., LL.D., F.R.S., 
PROFESSOR OF ZOOLOGY AT THE IMPERIAL COLLEGE OF SCIENCE AND TECHNOLOGY. 
WITH LITHOGRAPHIC PLATES AND TEXT-FIGURES. 
J. & A. CHURCHILL, 
LONDON. 
7 GREAT MARLBOROUGH STREET. 
1917. 
Adlard & Son & West Newman, Ltd.,] 
[London and Dorking. 
