NOV ^» 1899 



New Series, No. 168 (Vol. 42, Part 4). Price lOs. 



SEPTEMBER, 1899. 



THE 



QUARTERLY JOURNAL 



OF 



MICROSCOPICAL SCIENCE. 



EDITKU BY 



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



nONORABV FELLOW Or EXETER COLLEGE, OXt'OBD ; COB RESPONDENT OF THE INSTITUTE OF FRANCE, 



AND OF THE IMPERIAL ACADEMY OF SCIENCES OP ST. PETERSBURG, AND OF THE ACADEMT 



OF SCIENCES OF PHILADELPHIA; FOREIGN MEUBER OF THE ROYAL BOHEMIAN 



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



ASSOCIATE OF THE ROYAL ACADEMY OF BELGIUM; HONORARY MEMBER 



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 THE BRITISH MUSEUM; FULLERIAN PROFESSOR 



OF PHYSIOLOGY IN THE ROYAL INSTITUTION OF GREAT BRITAIN. 



WITH THE CO-OPERATION OF 



ADAM SEDaWICK:, M.A., F.R.S., 



FELLOW AND TUTOR OF TRINITY COLLEGE, CAMBRIDGE; 

 AND 



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



LINACRE PBOFESSOR OF COMPARATIVE ANATOMY AND FELLOW OF MERTON COLLEGE, OXFORD; 

 LATE FELLOW OF ST. JOHN*S COLLEGE, CAMBRIDGE. 



WITH LITHOGRAPHIC PLATES AND ENGRAVINGS ON WOOD. 



LONDON: 

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



1899. 



Adliird and Son,] [Bartholomew Close. 



