Biology of the INIembracidae of the Cayuga Lake Basin 353 



supposed stink glands (Buckton, 1903:18), but no signs of the latter 

 structures are shown in histological preparations. 



The male genitalia, while comparatively simple in structure, are extremely 

 interesting and are well deserving of more serious stud}^ than has been 

 given to them in the past. Occasional attempts have been made to use 

 the male genitalia for systematic purposes, but with little success. It is 

 not unreasonable to believe, however, that these structures, which have 

 proved of so much value in other groups of insects, should be equally 

 distinctive in the Membracidae if the characters are patiently diagnosed 

 for a large number of genera. It may naturally be supposed that sexual 

 organs undergo less change when the insects are forced into new conditions 

 and environments tha.n do motor or protective structures, and, being less 

 plastic, would preserve their characters and readily yield themselves 

 to generic classifications. A tentative study has seemed to show that this 

 is indeed the case. The organs have become modified in form and have 

 developed various types of claspers, styles, and prongs, ])ut the necessity 

 of retaining the function of the organs has kept these modifications within 

 bounds. Fowler (1894-97:2) states, regarding the Membracidae: 



It is probable that good characters may eventually be found in the male organs in certain 

 genera; but, except in one or two cases, I have found them of very little practical value as 

 yet, and this will be the case until more material for dissection is pro\'ided. 



The same author has, however, used these characters successfully 

 to distinguish the genera Ceresa and Stictocephala (pages 87, 102, 108, 

 of same reference), and the differences noted appear to be well chosen 

 and entirely satisfactory. Commenting on this character Van Duzee 

 (1908 a: 42), in his discussion of the genus Stictocephala, states: 



Canon Fowler in the Biologia does not trust to the form of the pronotimi but claims to 

 have found other characters in the form of the male genitaha that are sufficient. I have 

 however been unable to detect any such characters as he mentions without dissection of 

 the insect, which generally is out of the question, and prefer to distinguish the genus on the 

 form of the pronotum which I consider amply sufficient. 



Van Duzee's criticism is well taken in so far as regards the difficult}^ 

 of examination. This, indeed, is the objection to the use of the genital 

 characters in the family. It is practically impossible to determine their 

 structures without the destruction of the insect, and this, as Van Duzee 

 states, is often entirely out of the question. The usual methods of 

 relaxing or spreading the specimen, or the softening and pulling out of the 



