THE WINGS OF A CICADA 



271 



This has now been done in the case of representatives of each of the 

 families of this order, with the result that the homopterous type of wing- 

 venation is now well-known. The first work of this kind in this field was 

 by Comstock and Needham ('gS-'gg) who traced the development of the 

 wing-veins of a cicada. Ten years later Miss Patch ('09) studied the 

 development of the wing-veins of Aphididse, Psyllidae, Aleurodidse, and 

 Coccidas; and still later, Funkhouser ('13) determined the homologies of 

 the wing-veins of the Membracidse. In the same year there appeared two 

 papers by Professor Z. P. Metcalf, one on the wings of the Jassidse (Metcalf 

 '13a), and one on the wings of the Fulgoridas (Metcalf '13b); and more 

 recently this author has completed the series by a paper on the wing-veins 

 of the Cercopidas (Metcalf '16). Abstracts of each of these papers except 

 those on Fulgoridas and Cercopidas are given in the following pages. 



In addition to these papers, each of which treats of the wings of a family 

 of the Homoptera, Dr. Karel Sulc ('11) has made a careful study of the 

 tracheal development in the successive stages in the development of the 

 wings of a cercopid, PhilcBnus lineatus. 



(b) THE WINGS OF A CICADA 



The development of the wing-veins of a cicada was traced by Comstock 

 and Needham by a study of a series of nymphs of different ages and recently 



emerged adults. The results 

 obtained were exceedingly 

 gratifying. We had antici- 

 pated encountering much 

 difficulty in determining the 

 homologies of the wing-veins 

 of the Homoptera. We were 

 filled with delight, therefore, 

 when we found within this 

 order, preserved almost un- 

 changed, what we had come 

 to regard, from a study of 

 other orders, as the primi- 

 tive type of wing- venation. 

 The following account of 

 the development of the 



Fig. 270. — The fore wing of a voung nvmpli of 

 a cicada (After C. & N.). 



wing-veins of a cicada is abstracted from our joint paper. 



The close correspondence of the wing-venation of a cicada with the 

 primitive type is not obvious if one studies only the wings of the adult 

 (Fig. 269); for in this stage there is a massing of several veins along the 

 costal margin of the wing, and the cross-veins have the same appearance as 

 the branches of the primary veins. 



