Ml 17 1899 



New Series, No. 166 (Vol. 42, Part 2). Price 10s. 



T S" S^n MAY, 1899. 



THE 



QUARTERLY JOURNAL 



OF 



MICROSCOPICAL SCIENCE. 



EDITKI) BY 



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



HONORARY FELLOW OF EXElER COLLEGE, OXFORD ; CORRESPONDENT OF THE INSTITUTE OF FRANCE, 



A?ID OF THE IMPERIAL ACADEMY OF SCIENCES OV ST. PETERSBURG, AND OF THE ACADEMY 



OK SCIENCES OF PHILADELPUIA ; FOREIGN MEMBER OF THE ROYAL BOHEMIAN 



SOCIETY OF SCIENCES, AND OF TH -: ACADEMY OF THE MNCEI OF ROME; 



ASSOCIATE OF THE ROYAL ACADEMY OF BELGIUM ; HON URARV MEMBER 



OF THE NEW YORK ACADEMY OF SCIENCES* AND OF THE 



CAMBRIDGE PHILOSOPHICAL SOCIETY, AND OF THE ROYAL 



PHYSICALSOCIETY OF EDINBURGH ^ HONORARY 



MEMBER OF THE BIOLOGICAL SOCIETY 



OF PARIS ; 



DIRECTOR OF THE NATURAL HISTORY DEPARTMENTS OF THE BRITISH MUSEUM; FULLERIAN PROFESSJR 



OF PHYSIOLOGY IN THE ROYAL INSTITUTION OF LONDON. 



WITH THE CO-OPERATION OF 



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



FELLOW AND TUTOU OK TBIMTY COLLEGE, CAMBRIDGE; 



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



WITH LITHOGRAPHIC PLATES AND ENGRAVINGS ON WOOD. 



LONDON : 



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



1899. 



Adlud and Son,] 



[Barthotomew Close. 



