Septembee 26, 1913] 



SCIENCE 



443 



that we must have uniform and consistent 

 law, as has been stated by a recent contributor 

 to the discussion, if we desire a stable system 

 of nomenclature; in fact it goes without say- 

 ing that this is quite essential. 



But sundry knotty problems arise. For 

 example when we observe in a recent cata- 

 logue that the word Sunius, for a well-known 

 genus of beetles, which we have known hith- 

 erto only by that name, which our fathers and 

 grandfathers knew only by that name, which 

 in fact is the only name by which the genus 

 has been known in virtually the entire domain 

 of literature, must be changed and replaced 

 by AstenuSj we pause to ask why. It may be 

 admitted that some one connected with the 

 catalogue has gone back and at least thought 

 he understood that the original diagnosis — 

 these old descriptions being almost meaning- 

 less nine times out of ten — of Astenus, applied 

 better to what we have known as Sunius than 

 to anything else; but we are given no visible 

 evidence whatever. Are we blindly to change 

 the lifelong conception of several generations 

 and reverse all published literature of the 

 genus, on the authority of a guess and with- 

 out presentation of any sort of proof? The 

 language of the original description must 

 alone afford this proof, for there is no way of 

 knowing that the original type label may not 

 have been shifted in some way, if the type 

 chance to be in existence. 



The pity of the interminable tangle may be 

 reduced to this: If these over-zealous advo- 

 cates of strict priority had only refrained 

 from such publication until some system could 

 be formulated, it would have been possible to 

 adopt a uniform and consistent law which 

 need not be necessarily that of rigid priority. 

 One that might, for example, be analogous to 

 the legal rule of exemption after a certain 

 time limit. That is : If a genus name has not 

 been challenged or corrected during a con- 

 tinuous period of say sixty or seventy years 

 after its introduction in the commonly ac- 

 cepted sense, then it is to be considered per- 

 manent. This is absolute and consistent law 

 and nothing else. 



But the enthusiastic explorers of antiquity 

 have spoiled this otherwise available recourse 

 and I am free to confess that, as matters now 

 stand, there seems to be no rational way out 

 of the trouble but definitely to adopt the law 

 of absolute priority. I would, however, only 

 accept the identifications made by a competent 

 commission, which should be compelled to 

 publish its results in the fullest and broadest 

 possible manner and in such a convincing 

 way, by adducing the necessary proofs, that 

 there could be no just ground for dissent. I 

 feel that the enthusiasts aforesaid have com- 

 pelled this course, because if we now use the 

 old genus name Ips^ for example, without fur- 

 ther qualification, one would not know whether 

 we refer to a Nitidulid or a Rhynchophorid 

 beetle {T amicus Latr.), to give only one in- 

 stance among many. 



So the very chaos which has come about 

 through premature efforts to adhere to the 

 law of strict priority now forces the adoption 

 of that law, but only in the rigid way sug- 

 gested above. In other words, incontrovert- 

 ible evidence must be clearly and widely pub- 

 lished, proving that the change is necessary. 

 This opens up another vexing field of dispute. 

 The subject is really serious and should be 

 given the attention of the ablest natural his- 

 torians now and without further delay, so that 

 a secure foundation may be laid for future 

 generations. Other work should be laid aside 

 until this foundation is secure. 



Thos. L. Casey 



"Washington, D. C. 



SCIENTIFIC BOOKS 



Geometrical Optics. By Archibald Stanley 

 Percfval. London, Longmans, Green, and 

 Company. 1913. Pp. vi + 132. 

 This volume, issued recently, is intended 

 for medical students as a text-book intro- 

 ducing them to so much of optical theory as 

 may be necessary for the ophthalmic surgeon. 

 The mathematics of the subject is hence free 

 from applications of calculus, but the algebra 

 involved is enough to cause most American 



