RECENT ADVANCES IN 

 ENTOMOLOGY 



CHAPTER I 

 SOME ASPECTS OF MORPHOLOGY 



1. Segmentation of the Head, p. 4. 2. Wing Venation, p. 16. 

 3. The Metameric Appendages, p. 21. A. Thoracic Appendages, 

 p. 23 ; B. The Pleura, p. 28 ; C. The Primitive Insect Leg, p. 31 ; 

 D. The Cephalic Appendages, p. 32. 



The importance of an adequate and exact knowledge of 

 morphology has become increasingly evident in connection with 

 many aspects of entomology. Two notable text-books have 

 appeared within the last four years — one by Weber (1933) in 

 Germany, and the other by Snodgrass (1935) in the United 

 States. A perusal of these two works will make it evident to the 

 reader that the subject is emerging on a more exact and scientific 

 footing than hitherto. While morphology is essentially a 

 descriptive subject, it is becoming less divorced from function. 

 In dealing with exoskeletal organs and parts, not so much emphasis 

 is being laid upon sclerites and sutures alone, as primary criteria, 

 and more recognition is being accorded to the underlying 

 musculature. The morphology of the labium, for example, when 

 studied in conjunction with the musculature, is becoming better 

 understood and placed upon a surer basis. The requirements of 

 taxonomy, alone, will long provide a field for the application of 

 morphological knowledge, and advances in the latter will gradually 

 influence the systematic side of entomology. Progress in this 

 direction is naturally very slow, since it is only the established, or 

 more or less stabilised, morphological conclusions that concern 



K.A. ENTOMOLOGY. 1 1 



