QUARTERLY JOURNAL 



MFCR08C0PICAL SCIENCE. 



EDITED BY 



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



; CORKKSPONDE.NT OF THE IXSTITUTE OK FRANCE, 

 ; OF ST. PETERSBURG, AND OF THE ACADEMY 

 GN MEMBER OF THE ROYAL BOHEMIAN 

 ACADEMY OF THE LINCEI OF ROME; 

 { OF BELGIUM; HONORARY MEMBER 

 f OF SCIENCES. AND OF THE 



SOCIETY, AND OF THE ROYAL 

 IDINBURGU ; HONORARY 

 MEMBER OF THE BIOLOGICAL SOCIETY 



OF Paris; 



URAL HISTORY DEPARTMENTS OF THE BRITISH MUSEUM; FULLEHIAN PROFESSOR 

 K PHYSIOLOGY IN THE ROYAL INSTITUTION OF GREAT BRITAIN. 



HONORARY FELLOW OF EXElER COLLEGE, OX FO K 



AND OF THE IMPERIAL ACADEMY OF SCIENC 



OF SCIENCES OF PHILADELPHIA; FORI 



SOCIETY OF SCIENCES, AND OF TH' 



ASSOCIATE OF THE ROYAL ACADE 



n F THE SEW YORK ACADE 



CAMBRIDGE PHILOSOPHIC. 



PHYSICAL SOCIETY OI 



WITH THE CO-OPERATION OF 



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



FELLOW AND TUTOR OF TRINITY COLLEGE, CAMBRIDGE ^ 



AND 



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



VOLUME 42. -Neav Series. 

 Mit^ l'itl:|oc)rap^it ^latts airb (^iigrabings on S^oob 



LONDON: 



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



1899. 



