New Series, No. 173 (Vol. 44, Part 1). Price 10s. 



'7 r^^ NOVEMBER, 1900. 



QUARTERLY JOURNAL 



MICROSCOPICAL SCIENCE. 



EDITED BY 



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



HONORARY FELLOW OF EXETER COLLEGE, OXFORD ; CORRESPONDENT OF THE INSTITl'TE OK FRANCF, 



AND OF THE IMTEHIAL ACADEMY OF SCIENCES Ot ST. PETERSBURG, AND OF THE ACADEMY 



OF SCIENCES OF PHILADELPHIA; FOREIGN MEMBER OF THE ROYAL BOHEMIAN 



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



ASSOCIATE OF THE ROYAL ACADEMY OF BELGIUM; HONORARY MKMBKK 



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; FULLHRIAN P ROF KS::<<i II 



OF PHYSIOLOGY IN THE ROYAL INSTITUTION OF GREAT BRITAIN. 



WITH THE CO-OPERATION OF 



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



PEM.OW AND TUTOR OF TRINITY COLLEGE, CAMBRIDGE; 



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



AND 



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



BETEB PBOKKSSOB OF ZOOLOGY IN THE OWEXS COLLEGE, M ANCIIF.ST K K . 



WITH LITHOGRAPHIC PLATES AND ENGRAVINGS ON WOOD. 



LONDON : 

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



1900. 



Adlard and Son,] 



[Bartholomew Close 



