June 4, 1897. ] 



SCIENCE. 



^11 



It is stated iu the daily papers tliat Dr. 

 Anton eo Crocichia has been elected to the chair 

 of biology in the Catholic University, Washing- 

 ton. 



Dk. J. S. Ely, professor in the Woman's 

 Medical College, New York, has been elected 

 professor of the theory and practice of medi- 

 cine in the Medical School of Yale University. 



We learn from the Botanical Gazette that Dr. 

 E. B. Copeland has been appointed assistant 

 professor of botany in the University of Indi- 

 ana in place of Dr. Geo. J. Peirce, who resigned 

 to accept a similar position, in charge of plant- 

 physiology in the Leland Standfoi-d Junior 

 University. 



Dr. Beck, of the University of Lemberg, has 

 been promoted to a full professorship of phys- 

 iology, and Dr. Konrad Zeisig has been made 

 second professor of physics in the Polytechnic 

 Institute of Darmstadt. Dr. Deichmiiller, ob- 

 server in the observatory at Bonn, has been 

 appointed associate professor. Dr. Ludwig 

 Heim, of Wurzburg, has been called to an as- 

 sociate professorship of bacteriology in the 

 University of Erlangen. Dr. Hillebrand has 

 qualified as decent in astronomy in the Univer- 

 sity at Vienna. 



DISCUSSION AND COBBESPONDENCE. 

 THE DISCRIMINATION OF SPECIES AND SUB- 

 SPECIES. 



De. Merriam's paper in Science for May 

 14 (N. S., Vol. v., No. 124, pp. 753-758), en- 

 titled ' Suggestions for a New Method of Dis- 

 criminating between Species and Subspecies,' 

 opens up a question of immense interest and far- 

 reaching importance, respecting which there is 

 room for two widely divergent opinions, both 

 susceptible of support by arguments of con- 

 siderable weight. Dr. Merriam cites the purely 

 conventional and arbitrary rule adopted in the 

 A. O. U. ' Code of Nomenclature ' for deciding 

 the status of closely related forms with refer- 

 ence to whether they are to be ranked as 

 species or subspecies, and calls attention to the 

 well-known inconsistencies sometimes resulting 

 from its use. The failure of the rule to yield 

 always satisfactory results is not due to the prin- 

 ciple involved, but to the imperfection of our 



knowledge respecting what closely related forms 

 intergrade and what do not. Consequently, it is 

 urged, a stable nomenclature for such forms can- 

 not be attained under this rule till we have a 

 complete knowledge of the relations of such 

 forms ; in the meantime their status will be un- 

 stable, and their nomenclature, in this respect, 

 subject to change as our knowledge of them in- 

 creases. 



The first part of the rule as summarized by 

 Dr. Merriam (1. c, p. 753) — to wit: "Forms 

 known to intergrade, no matter how different, 

 must be treated as subspecies and bear trinomial 

 names" — presents no difficulty of application 

 and can be carried into efiect without imperil- 

 ing stability of nomenclature. The second part 

 — namely, " forms not known to intergrade, no 

 matter how closely related [or, rather, how 

 closely they resemble each other] ^ must be 

 treated as full species and bear binomial names' ' 

 — is difficult to apply always consistently. As 

 Dr. Merriam says, ' ' only in a small percentage 

 of cases does an author have at his command a 

 suflBciently large series of specimens, from a 

 sufficient number of well-selected localities, to 

 enable him to say positively that related forms 

 do or do not intergrade;" and that conse- 

 quently " authors usually exercise their individ- 

 ual judgment as to the probable existence or 

 non-existence of intergradation," based, of 

 course, on the nature of the differences, the 

 geographical relationship of the forms, and on 

 general grounds —on what is known to happen 

 in other similar cases. Hence, naturally, some 

 degree of inconsistency results in the use of tri- 

 nomials, they being frequently employed where 

 conclusive evidence of intergradation is lacking, 

 though strongly indicated by the circumstances 

 of the case. When later information shows 

 that the true relationship of the forms in ques- 

 tion has not been correctly indicated, their 

 status must be changed, either from that of a 

 species to a subspecies, or the reverse, as the 

 case may require. But this, while undesirable, 

 is not a serious change, since the 'special' name 

 (specific or subspecific) is necessarily retained — 

 a change far less important than the substitu- 

 tion of one name for another, as not infre- 

 quentlj' becomes imperative from other causes. 



The real question, then, is whether we can 



