SCIENCE 



Editokial Commtttek : S. Ukwcosib, Jlatbematics ; E. S. Woodtvakd, Jlecbanics ; E. C. Pickkking, 



Astronomy; T. C. JIexdexhall, Pbysics ; R. H. Thueston, Engineering; Ik A Remskx, Chemistry; 



J. Lk Coxte, Geology; "W. JI. Davis, Physiography; O. C. JIaesh, Paleontology; TV. K. Brooks, 



C. Hakt Mereiam, Zoology; S. H. Sctjddek, Eutomologj; C. E. Bessky, N. L. Britton, 



Botany; Hexey F. Osbokx, General Biology; C. S. JIixoT, Embryology, Histology; 



H. P. BowDiTCH, Physiology; J. S. Billings, Hygiene ; J. SIoKeex Cattell, 



Psychology; Damel G. Beinton, J. TV. Powell, Anthropology. 



Friday, Mat 20, 1898. 



COMTENTS: 



A Precise Criierion of Species: — 



A. The General ' Jilethod : Peofessok C. B. 



Davexpoei 6S5 



£. The Chief Differential and Spccijic vs. Individ- 

 ual Characters: J. W. Blax'kixship 690 



Julius Sachs (11) : Peofessok K. Goebel 695 



The Breeding of Animals at Woods Boll during the 

 Month of April, 1S9S : A. D. Mead ". 702 



Current Xoles on Pht/siography : — 



The Origin of Pugct Sound : Tlie Plains of Rus- 

 sia ; Tidal Prohlems : Peofessok W. 51. Davis..704 



Current Xotes on Attthropologp : — 



Slst Peabody JIuseum JReport ; Tlie Aims of Eth- 

 nology; The Araucanian Tongue: PkofkssoE 

 D. G. Bkixtox 706 



Notes on Inorganic Chemistry: J. L. H 707 



Seie7itific Notes and News: — 



Ciri'l Serrice Examinations in Science; Museums 

 of the Science and Art Department, London; Ob- 

 servatories on the Azores; General 708 



University and Educational News 712 



Discussion and Correspondence : — 



Pemarl-s on the Method of the ' Neio Psychology ' 

 icith Memory: HiEAJl il. Staxley. The Cctuses 

 of Natural Arches: F. S. Dellexbaugh 713 



Scientific Literature: — 



Wilder' s System of Nomenclature: Pkofessoe 

 Feaxk B akee. Barringcr's Description of Min- 

 erals: Peofessoe W. S. Bayley 715 



Scientific Journals 717 



Societies and Academies : — 



American Mathematical Society: PeofessOE F. 

 K.Cole. The Philosophical Society of Washing- 

 ton : E. D. Prestost. New York Section of the 

 American Chemical Society : De. DueaxdWood- 

 3IAX. Academy of Natural Sciences of Philadel- 

 phia: Dk. Edwaed ,I. Nolax 718 



Neto BooJcs 720 



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

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

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



A PBECISE CBITEBION OF SPECIES. * 

 A. 27(6 General 3Iethod. By C. B. Daven- 

 port, Harvard University. 

 The aim of this paper is to propose a 

 definite metliod of judging whether two 

 closely allied and iutergrading groups of 

 organisms belong to distinct species or only 

 to subspecies or varieties. 



I. The Present Criteria of Species. The 

 practical criteria employed at the present 

 time to distinguish a species from a variety 

 are either one of the two following : 1. A 

 certain considerable degree of dissimilarity 

 in characters — of divergence between the 

 types. 2. A sharp demarcation between 

 the types, their mutual isolation, or, in 

 other words, the absence of iutergrading 

 forms. Of these two criteria, that of diver- 

 gence is most generallj- employed ; yet one 

 influential body — The American Ornitholo- 

 gists' Uuion — ^adopts the second in a strict 

 form. Its remarkable rule reads : " Forms 

 known to intergrade, no matter how differ- 

 ent, must be treated as subspecies ; forms 

 not known to intergrade, no matter how 

 closely related, must be treated as full 

 species." This clear cut rule does not seem 

 however to have been worked in practice.f 

 Nearlj' all naturalists, indeed, recognize a 



*Read before the Boston Society of Natural History, 

 April 6, 1S98. 



tSee, for example, the discnssion by Merriam, 

 Allen and Roosevelt in Science, Vol. V., pp. 753, 

 877 and 879. 



