6 THE GENESIS OF THE TERMINOLOGY 



characters: II, IV, VI, VIII, X. In the case of wings with an expanded 

 anal area the numbers XII and XIII are also used. 



The only so-called concave vein to which he applied a name is the 

 subcosta. 



In subsequent modifications of his system the six names used by him, 

 costa, subcosta, radius, media, cubitus, and anal veins have been adopted. 



The branches of the principal veins were designated by adding Arabic 

 numerals to the Roman numeral designating the principal vein. Thus the 

 branches of vein III are designated successively as IIIi, III2, III3, III4, 

 and Ills. 



It was unfortunate that Redtenbacher was misled by the erroneous 

 theory of alternating convex and concave veins elaborated by Adolph. The 

 result was that, although Redtenbacher recognized the homologies of the 

 main stems of the principal veins, he, in his efforts to apply this theory, was 

 led into many serious errors. The result is that the terminology now 

 adopted differs much in detail from that of Redtenbacher upon which it 

 was based. These differences are indicated in later chapters. 



Redtenbacher was also misled by the then commonly accepted view of 

 the paleontological data bearing on the evolution of wings. Stating this 

 view he writes (page 155) as follows: — • 



The geologically older Orthoptera and Neuroptera show a much richer 

 venation than the Coleoptera, Lepidoptera, Hymenoptera, and Diptera; 

 likewise among the Rhyncota, the oldest forms, the Cicadidse and the 

 Fulgoridffi, possess much more numerous veins than the Hemiptera. There 

 is apparently, then no doubt, that the oldest insect forms were provided to a 

 certain extent with a superfluity of veins, and that, in the course of develop- 

 ment, all the superfluous veins disappear by reduction, and, in this way a 

 simple system of venation was brought about. 



The acceptance of these two erroneous views, the theory of alternating 

 concave and convex veins and the belief that the first winged insects had 

 many wing-veins, did much to retard the progress of the efforts to establish 

 a uniform terminology of the wing-veins. 



Redtenbacher's adherence to the theory of Adolph was short lived, 

 however; for two years after the publication of his larger paper one 

 appeared, of which he was the junior author (Brauer und Redtenbacher, 

 1888), in which the theory of different origins of the concave and convex 

 veins is discredited. But there is no suggestion in this paper of a modifica- 

 tion of the Redtenbacher system of terminology of the wing-veins. 



With the appearance in 1891, 1892, and 1893 of papers by Dr. Erich 

 Haase and by Dr. Arnold Spuler, there began a series of modifications of the 

 Redtenbacher terminology. 



The first of these three papers was a brief abstract by Haase ('91) of 

 his conclusions regarding the development of the wing-veins of Papilio 



