232 WM. REES B. ROBERTSON 



ing to find loops in this stage, where, since they were dealing with 

 only straight-rod chromosomes, there could be none. And in 

 doing this they have attempted to see in these loops, so formed, 

 the evidence of end-to-end synapsis, misled probably by Mont- 

 gomery's ('03) work on Amphibia. He, it is true, was there 

 dealing with loops, since the Amphibia have ten pairs of V's, 

 and he correctly saw the constriction shown at the apices of these 

 loops; but these constrictions did not mean that telosynapsis 

 had taken place between one of the ends of each of a pair of V's; 

 on the contrary, they probably corresponded to the constric- 

 tion at the apices of the spermatogonial pair of V's, which were 

 here in parasynapsis. 



In those species, however, where some V's occur, as in Chorthip- 

 pus, one might expect a few of the loops characteristic of the 'bou- 

 quet' to appear. This may be seen in Davis's ('08) figure 48 

 of Stenobothrus. Finally, in those species where all or nearly 

 all the chromosomes are of this V-shaped type, we find the 

 nucleus in the 'bouquet-stage' with practically nothing but these 

 loops present, as the Schreiners have shown for Tomopteris 

 ('06a, figs. 20f, 22, 23, 25, 26), and Montgomery ('03, figs. 2, 

 3, 5), Janssens ('05, fig. 42), and the Schreiners ('06b, fig. 12) 

 for the Amphibia. 



I have not studied the 'bouquet' and the earlier synapsis 

 stages in Syrbula or Chorthippus, but only the later synapsis. 

 My first stage (figs. 149, 151, 163-168) corresponds, I believe, to 

 stage '//-' of Wilson ('12) and stages '/' of Davis ('08), since it 

 not only resembles these, but, like them, is immediately preceded 

 by a stage in which no regular spireme can be distinguished, 

 the chromatin being in a fine netlike condition, possibly the 'dif- 

 fused' stage {'g') of Wilson ('12, figs. 66, 67). 



As explained in the description (pp. 210-215), each autosome, 

 when it emerges from stage 'g,' consists of two longitudinal 

 strands in both Syrbula (fig. 149) and Chorthippus (figs. 163-167). 

 These two-strand spiremes resemble very much those of Pam- 

 phagus shown by Granata ('10, figs. 25-27) ; Dissosteira, Steiroxys, 

 Stenobothrus by Davis ('08, figs. 57, 58, 70, 83) ; Ceuthophilus, 

 by Stevens ('12, figs. 27, 28); Oncopeltus, by Wilson ('12, figs. 



