SCIENCE 



Editorial Committee : S. Nbwcomb, Mathematics ; E. S. Woodwaed, Mechanics ; E. C. Pickering, 



Astronomy; T. C. Mendbnhall, Physics; R. H. Thurston, Engineering; Ira Eemsen, Chemistry; 



J. Le Conte, Geology; W. M. Davis, Physiography; O. C. Marsh, Paleontology; W. K. 



Brooks, C. Hart Mbrriam, Zoology ; S. H. Scudder, Entomology ; N. L. Beitton, 



Botany; Henry F. Osboen, General Biology; H. P. Bowditch, Physiology; 



J. S. Billings, Hygiene ; J. McKeen Cattell, Psychology ; 



Daniel G. Beinton, J. W. Powell, Anthropology. 



Friday, January 29, 1897. 



CONTENTS: 



Cycle in the Life of the Individual {Ontogeny) and in 

 the Evolution of its own Group {Phytogeny) : 

 Alpheus Hyatt 161 



The Blackboard Treatment of Physical Vectors : C. 

 Babcs 171 



Zoological Notes : — 

 Natisen's Discovery of the Breeding Grounds of the 

 Posy Gull : T. S. JPalmee. Origin of Parasi- 

 tism in the Coiobird : O. Widmann 175 



Current Notes on Physiography : — 

 Branch Streams of the Schuylkill; Hann's Allge- 

 meine Erdkunde ; The Topographical Association ; 

 Notes: W. M. Davis. 177 



Current Notes on Anthropology : — 



The Game of Slaucala ; Oriental Items of Ethno- 

 logic Interest : D. G. Brinton 178 



Notes on Inorganic Chemistry: J. L. H 179 



Astronomical Notes : H.J 180 



Sdentifie Notes and News 181 



University and Educational News 185 



Discussion and Correspondence : — 



Simplified Spelling : G. K. Gilbert. An Ex- 

 planation of the so-called Pseudo-aurora : J. PAUL 

 GooDE 185 



Scientific Literature : — 



Catalogues des bibliographies geologiques : G. K. 

 Gilbert. JohonnoVs Principles and Practice of 

 Teaching; Jackman's Nature Study: Chaeles 

 Wright Dodge. Papers presented to the World's 

 Congress on Ornithology: C. F. Batcheldee...187 



Scientific Journals : — 

 Journal of Geology : H. F. B. Terrestrial Mag- 

 netism 190 



Societies and Academies : — 

 The Scientific Association of Johns Hopkins Uni- 

 versity : Chas. Lane Poor. The Anthropolog- 

 ical Society of Washington: J. H. MoCoEMlCK. 

 Washington Section of the American Chemical Soci- 

 ety : V. K. Chesnut. Boston Society of Natural 

 History : SAMUEL Hbnshaw. Geological Club of 

 the University of Minnesota: Chas. P. Berkey.192 



MSS. intended for publication and books, etc., intended 

 for review should be sent to the responsible editor, Prof. J. 

 McKeen Cattell, Garrison-on-Hudson, N. Y. 



CYCLE IN THE LIFE OF THE INDIVIDUAL 



(ONTOGENY) AND IN THE EVOLUTION 

 OF ITS OWN GROUP (PHYLOGENY).*' 



The organic cycle, as generally under- 

 stood both by laymen and scientists, and 

 as usually described in literature, is, as a 

 rule, considered from a physiological rather 

 than structural point of view. The devel- 

 opment of the young, and the attainment 

 of the adult or comparatively permanent, 

 stage completes the progressive stages. 

 Old age, accompanied by losses of charac- 

 teristics and functions and consequent 

 weakening of the body, is retrogressive and 

 brings on second childhood, thus complet- 

 ing the cycle in the ontogeny. 



My purpose to-night is to show that the 

 cycle is also represented in the life history 

 of the individual by definite structural 

 changes, and that these have direct correla- 

 tions with the history of the changes in the 

 forms of the group while evolving in time.f 



The fundamental discoveries that are 



* This paper was in large part read as a general 

 summary of the phenomena of cycles, before the 

 American Academy in Boston, but does not assume 

 to be an exhaustive or even complete account of the 

 literature or theoretical views treated of. 



t These correlations have been more fully stated in 

 a number of publications by the author, especially 

 'Genesis of the Arietidse,' Smithsonian Contribu- 

 tion, 673, and Mem. of Mus. of Comp. Zoology, Vol. 

 XVI. ; ' Bioplastology and the Belated Branches of 

 Scientific Research,' Proo. Bost. Soc. Nat. Hist., 

 XXVI. ; and ' Phylogeny of an Acquired Character- 

 istic,' Proc. Am. Phil. Soc, XXXII., No. 143. 



