THE CHROMOSOMES OF THE CERCOPID^E. 



ALICE M. BORIX ,. 



The chromosomes of at least four species of this family have 

 been already studied, one by Dr. N. M. Stevens, 1 and three by 

 the writer. 2 These three species which I have already studied 

 were collected at Cold Spring Harbor in 1907 and identified by 

 Mr. E. P. Van Duzee as Clastoptera obtusa, Aphrophora quad- 

 rangularis, and Aphrophora quadrinotatu . The species studied 

 by Dr. Stevens was collected at South Harpswell in 1906 and 

 identified at the time as Aphrophora quadrangularis, but the 

 cytological differences from the Cold Spring Harbor material 

 which was surely Aphrophora quadrangularis made Dr. Stevens 

 later question the identification of the Harpswell material. The 

 reduced number of chromosomes is different in all of these species, 

 12 in the Harpswell form, 15 in Clastoptera obtusa, n (12?) in 

 Aphrophora quadrangularis, and 14 in Aphrophora quadrinotata. 

 In other respects, the spermatogenesis in one species resembles 

 that of the others, except for the Harpswell form which differs 

 in several points : the odd chromosome of the early growth stages 

 of the primary spermatocytes is long and rodlike; in later stages 

 two M-chromosomes appear ; and the odd chromosome in the equa- 

 torial plates of the primary spermatocytes is one of the medium- 

 sized chromosomes. In the other species, the odd chromosome in 

 the growth stages is never rodlike, but always rounded, and no 

 M-chromosomes ever appear in the growth or division stages; 

 the odd chromosome in the equatorial plates of the first sperma- 

 tocyte division and in the sideview of the spindles appears to be 

 one of the smaller chromosomes. In 1909, I collected material of 

 the common European spittle insect, Aphrophora spumaria, at 

 Eisenach, for chromosome study, and this summer at Woods 

 Hole a chance to study one more species of this family was 



1 Stevens, N. M., 1906, "Studies in Spermatogenesis," Part II., Carnegie Inst., 

 Washington. 



2 Boring, A. M., 1907, "A Study of the Spermatogenesis in Twenty-two Species 

 of the Membracidae," etc., Jour. Exp. Zoo/., IV 7 ., p. 469. 



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