216 WM. EEES B. EOBERTSON 



(2) In Syrbula these rod-shaped autosomes and the sex chromo- 

 some may each be recognized in a group by their relative lengths. 

 Almost the same size relations may be seen in the sex chromo- 

 some, the five pairs of rods and the six pairs of limbs of the three 

 pairs of V's of Chorthippus. 



(3) A constriction, a clear, non-staining bridge, and an at- 

 traction fiber occur at the apex of each of the V's in sperma- 

 togonia. These conditions may be traced in spireme stages, 

 the prophases, metaphases, and anaphases of first spermato- 

 cytes, in second spermatocytes, and in spermatids. Such con- 

 strictions divide the members of each pair of V's into two pairs 

 of rods, equivalent in length in each case to the 5's and 9's, the 

 7's and ll's, and the 8's and lO's of Syrbula. 



(4) The limbs of the paired V's in late synapsis stages, pro- 

 phases, and metaphases of the first spermatocytes behave like 

 the 5's, 7's, 8's, 9's, lO's, and ll's of Syrbula, in that they form, 

 during these stages, rod-shaped, cross-shaped, horseshoe-shaped, 

 and ring-shaped tetrads, depending, as in the rods of Syrbula, 

 upon the lengths of the pair of limbs in each case. They agree 

 also in the characteristic appearance that each such tetrad gives 

 in the late metaphase and in anaphases. The diads resulting 

 from these behave similarly in the second spermatocytes of 

 both genera. 



(5) In conclusion, therefore, I believe that the three pairs of 

 V-autosomes of Chorthippus are the equivalent of the six pairs 

 of rod-autosomes of Syrbula, — the 5's, 7's, 8's, 9's, lO's, and ll's, 

 — and that the remaining five pairs of rod-autosomes and the 

 sex chromosome of Chortippus are likewise the equivalent 

 of the I's, 2's, 3's, 4's, 6's, and sex chromosome of Syrbula. If 

 this be so, then we may consider each of these three pairs of 

 V's to be a compound chromosome, and that, therefore, the 

 Truxalinae have the number twenty-three, characteristic of 

 Acrididae. 



S. Oedipodinae (Acrididae) 



The third subfamily of the Acrididae is here represented bj' 

 Chortophaga viridifasciata and Dissosteira Carolina (figs. 190, 



