— 8i — 



word vein would be omitted and the legends would read 

 i st III— V, 2d III— V, etc. 



NOTE. — The above statement will serve the needs of the beginning 

 student. But the advanced student will find in using the works of 

 certain writers that important modifications of this system of number- 

 ing the wing-veins have been proposed. For such students it seems 

 desirable to make the following statement, which may be omitted by 

 the beginner. 



There have been several attempts to establish a uniform nomenclat- 

 ure for the wing-veins of insects. Of these that of Redtenbacher* is the 

 most important, being based on a much more extended study of the 

 subject than that made by any other author. He was the first author 

 to work out a system and apply it to all orders of insects. 



The names and numbers of the wing-veins given above are those 

 adopted by Redtenbacher, except the names premedia, postmedia and 

 anal furrow, which were proposed by the writer. f These veins were 

 recognized and numbered, as above, by Redtenbacher, but not 

 named. 



Redtenbacher, however, took the -^asgjs^^^^^BtSS?^ 



wing of a May-fly as the typical in- ---"'"" ~^^S^kw^^^^ ■' 

 sect's wing, and endeavored to find ^-jjS^^^?^.'' ,/ 



all the principal veins of this wing \ ^^^^^^^"' 



in the wings of insects of each of the • \ vSv^*^ 



other orders. Later it was shown by ""-v. -' 



SpulerJ and by the writer^ that in fig. 4.— Wing of Platephemera. 



several orders of insects at least 



there is no longitudinal vein between radius and media and 

 none between media and cubitus. The writer also pointed out the 

 fact that the veins premedia and postmedia were also wanting in the 

 wings of paleozoic insects, || and suggested that these veins had been 

 developed secondarily in the May-flies, as a result of the corrugation 

 of the wings of those insects.^ In support of this view, attention was 

 called to the fact that in the oldest May-fly known, Platephemera 

 antiqua of the Devonian age (Fig. 4), the cells of the wing are polyg- 

 onal in the areas traversed by these veins, while in the modern May- 



* Josef Redtenbacher, Vergleichende studien iiber das Fliigelgeader der Insecten. 

 Ann. des k. k. natui historischen Ho/museums, IVein. Bd. I. s. 153-232, t. IX-XX. 



t J. H. Comstock, Evolution and Taxonomy, The Wilder Quarter- Century Book, 

 pp. 37-114, PI. I-III. 



J A. SruLER, Zur Phylogenie und Ontogenie des Fliigetgeaders der Schmetterlinge, 

 Zeiischrifl fur wissenschaftliche Zoologie. Bd. 1,111, s. 597-646, t. XXV, XXVI. 



g J. H. Comstock, Evolution and Taxonomy. || /. c, pp. 66, 67. 



f It may be, however, that these veins are detached branches of media. 



