204 WM. REES B. ROBERTSON 



6) is drawn from each of several cells showing the split and es- 

 pecially the large knobs, at the distal end, so common in this 

 species. Sometimes the constriction is so great that one could 

 imagine the knob to be a small attached chromosome. Is it 

 possible that this knob corresponds to one of the smaller of the 

 twenty-three or twenty-four chromosomes of the Acrididae? 

 It might thus help to account for the smaller number, thirteen 

 or fourteen, of the Tettigidae. 



Figures 108 to 110 are of mitoses in male somatic cells from 

 fat-body tissue. Here the chromosome numbers and their 

 relative sizes are the same (Table XVIII) as in germ cells. 



Figures 111 to 119, and 121 are metaphases of first spermat- 

 ocytes showing number and size relations of chromosomes as 

 before. Figure 121 lacks one pair (5's) due to sectioning. The 

 slight inequality of 5's and 6's and the absence of as large a gap 

 between the 2's and 3's as exists in Acridium and Paratettix are 

 very evident. 



Figures 122 and 123, representing two anaphase stages of 

 the first spermatocyte, show that all chromosomes except 5x 

 divide. This is probably the reduction division. The sex 

 chromosome tends to drop behind the others in the latter part of 

 its passage to the pole (fig. 123), though it starts ahead of them 

 (fig. 122). 



Figures 124 to 127 are metaphases of second spermatocytes. 

 There are two sorts of cells, some containing seven, others only 

 six chromosomes. The relative sizes (figs. 124, 125) are accu- 

 rately shown. Nos. 5 and 6 are almost alike ; 5x is clearly between 

 4 and 5. Further, 4 and 3 are nearly alike, as are also 1 and 2. 

 One of the latter (no. 2), however, is always more slender than 

 the other. This is seen even in first spermatocyte divisions, 

 and it may be this autosome that condenses before the others 

 in the first spermatocyte prophase stages (no. 2, figs. 65, 66). 

 Figure 126 represents a cell sister to that seen in figure 127. 

 These show that all chromosomes, including 5a;, are split in the 

 second spermatocyte division. 



The metaphases and anaphases of the first spermatocyte, 

 shown in figures 128 to 135, are from young specimens belong- 



