APR 5 1901 



New Series, No. 174 (Vol. 44, Part 2). Price 10s. 



") ^'^n MARCH, 1901. 

 THE 



QUARTERLY JOURNAL 



OF 



MICROSCOPICAL SCIENCE. 



EDITEIJ BY 



E. RAY LANKESTER, M.A., LL.D., F.R.S., 



JNOBARY FELLOW OK EXEfEK COM.EGK, OXFOR D ; CORRESPONDENT OF TUE INSTITUTE OF IKANCK, 



AND OF THE IMPERIAL ACADEMY OF SCIENCES Off ST- PETERSBURG, AN1> OF THE ACADFMV 



OF SCIENCES OF P HI LADELP HI A ; FOREIGN MEMBER OF TUE ROVAL DOIIRMIAN 



SOCIETY OF SCIENCES, AND OF THE ACADEMY OF THE LINCEI OF ROME; 



ASSOCIATE OF TUE ROYAL ACADEMY OF BELGIUM ; HONORARY 31EMBER 



OF THE NEW YORK ACADEMY OF SCIENCES, AND OF THE 



CAMBRIDGE PHILOSOPHICAL SOCIETY, AND OF THE ROYAL 



PHYSICAL SOCIETY OF EDINBURGH ; HONORARY 



MEMBER OF THE BIOLOGICAL SOCIETY 



OF PARIS; 



DIRECTOR OF THE NATURAL HISTORY DEPARTMENTS OF TUE BRITISH MUSEUM; LATi: F1'LLERIA\ 



PROFESSOR OF PHYSIOLOGY IN THE ROYAL INSTITUTION OF GREAT BRITAIN. 



WITH THE CO-OPERATION OF 



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



KKI.I.OW ANI> TllTOIl OF xruXlTV roI.I.EGK, CAMBKIDGE; 



W. F. R. WELDON, M.A., F.R.S., 



iTOMV J 



John's 

 AND 



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



BFVKK rnoIKSSOB Of KOOI.OGV IV Till; OWKNS COLLEGE, M.V \r II KSTK r . 



WITH LITHOGRAPHIC PLATES AND ENGRAVINGS ON WOOD. 



LONDON: 



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



1901. 



Aillard and Son,] 



[Bartholomew Close 



