New Series, No. 175 (Vol. 44, Part 3). 



'^ ^X*^. IVIAY, 1901. 



Price 10s. 



THE 



QUARTERLY JOURNAL 



MICROSCOPICAL SCIENCE. 



EDITED BY 



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



HONORARY FELLOW OF EXETER COLLEGE, OXPOR D ; 



AND OF THE IMPEItlAL ACADEMY OF SCIENCES 



OF SCIENCES OF PHILADELPHIA; FOttEIG 



SOCIETY OF SCIE.NCES, AND OF THE A 



ASSOCIATE OF THE ROYAL ACADEStY 



OF THE NEW YORK ACADEMY 



CORRESPONDENT OF THE INSTITUTE OF 

 OP ST- PETERSBCBG, AND OF THE ACAPEM 

 N MEMBER OF THE ROYAL BOHEMIAN 

 CADEMY OP THE UNCKI OF ROME ; 



OF Belgium; honorary membi;h, 



OF SCIENCES, AND OF THE 



CAM BRIDGE PHILOSOPHICAL SOCIETY, AND OF THE ROYAL 



PHYSICAL SOCIETY OF EDINBURGH ; HONORARY 



MEMBER OF THE BIOLOGICAL SOCIETY 



OF PABISj 



DIRECTOR OF THE NATURAL IIISTOBY DEPARTMENTS OF TUB BRITISH MUSEUM; LATE 



PROFESSOR OK PHYSIOLOGY IN THE ROYAL INSTITUTION OF GREAT BRITAIN. 



WITH THE CO-OPERATION OF 



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



rnLLOW AMD TUTOR Uf TRIXITT COM.KGE, CAMBRIDGE J 



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



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



BEYER PROFESSOR OF ZOOLOGY IN THE OWENS COLLEGE, MANCHESTER. 



WITH LITHOGRAPHIC PLATES AND ENGRAVINGS ON WOOD. 



LONDON: 

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



1901. 



Adiard and Son,] 



[Bartholomew Close. 



