1911] Composition of Taxonomic Papers 205 



Bad as color illusions are, mathematical illusions are worse. 

 The chapter on "Optics" ought to form the favorite reading of 

 many taxonomists. A difference of one millimeter on an insect 

 of 20 mm. length is slight ; but it makes a considerable difference 

 on an insect of 8 mm. It is a peculair experience to read in a 

 description of a beetle or any other insect "elytra twice the 

 width of the pronotum" and then find by actual measurement 

 that the pronotum is 4 mm. at its widest point while the elytra 

 are 10 mm. or more in length. Similarly with most other com- 

 parative measurements. When tested by the micrometer or 

 millimeter scale they will be found considerably aberrant. 

 Hence the urgent advisability to introduce exact measurements 

 instead of the unreliable optical method of comparison. 



One standard does exist in anatomical nomenclature, name- 

 ly the Comstock-Needham nomenclature of wing venation. 

 The merits of this system are undisputed and recognized by all 

 modern systematists. But instead of unreservedly adopting 

 a system the value of which they confirm, taxonomists inter- 

 mingle the antiquated miscellaneous wing nomenclature with 

 the logical modern terminology. As a result we are continually 

 thrown from one style of naming the veins to the other. This 

 may not be troublesome for the specialist. But if a student is 

 generally interested in entomology, he finds himself in a constant 

 quandary as to the special terminology of each particular order, 

 as they are easily confused; whereas the Comstock-Needham 

 nomenclature was especially designed to obviate this difficulty. 

 It is true, certain orders have certain appendages which it is 

 desirable to retain, e. g., for Neuroptera the thyridium cell and 

 end-forks, bees the subcostal cells, etc. These should be retained, 

 as they are special attributes of the respective order, family or 

 genus. But the fundamental principles of venation, as out- 

 lined by the Comstock-Needham nomenclature, are possessed 

 by all orders, viz., costa, subcosta, radius, media, cubitus and 

 anal vein. Why not use them instead of vein 1, 2, 3, 6, 8, 10, 

 etc.? The terminology is simpler, it is less aggravating, it is 

 more logical, and it is an aid to the student and worker. 



C. Nomenclature of Types. — Quite as important as specific 

 and anatomical nomenclature is the nomenclature of types. 

 Considerable attention has been given to the latter study in 

 recent years. As the various departments of natural history 

 are dependent mainly upon descriptions for the taxonomic 



