APHROPHORA QUADRANGULARIS. 47 



11 chromosomes, and the odd chromosome at a different level (b). 

 The latter is a view of the anaphase which one often gets at three foci 

 in one section. Figures 259, a and b, are equatorial plates of the sec- 

 ond mitosis with 11 and 12 chromosomes respectively. Figure 260 

 shows a side view of the second spindle in metaphase, and figure 261 

 in anaphase. Figures 262 and 263 are daughter plates from two 

 spindles showing the chromosome content of the two equal classes of 

 spermatozoa, one class containing 11 ordinary chromosomes, the other 

 11 ordinary chromosomes plus the odd heterochromosome, for the odd 

 chromosome divides with the others in the second spindle as in 

 Orthoptera (McClung and Sutton). 



In figures 264 and 265 (plate xv) are seen the telophase of the two 

 kinds of second spermatocytes, one (fig. 265) showing the divided odd 

 chromosome, which continues to Stain more deeply after the others 

 have become diffuse. All of the spermatids (figs. 266-268) contain, in 

 the early stages of development, a body (n) which stains like chroma- 

 tin, but increases in size from a small granule in the telophase (figs. 

 264, 265) to the large dense body (n) seen in figure 267. This is prob- 

 ably homologous with the chromatin nucleolus described for the 

 spermatids of the Coleoptera. In addition to this, in one-half of the 

 spermatid nuclei there is a condensed mass of chromatin which is 

 evidently the derivative of the odd chromosome of the spermatogonia 

 and spermatocytes (figs. 267 and 268, x). In common with the sperm- 

 atids of other Hemiptera these show two masses of archoplasm, the 

 larger of which forms the sheath (s) of the axial fiber of the tail, and 

 the smaller the acrosome (a). The axial fiber grows out directly from 

 the centrosome, on either side of which there is a dense band forming 

 the lateral boundary of the middle piece. It will be seen that the 

 odd chromosome of Aphrophora is in its behavior precisely like the 

 typical Orthopteran " accessory " of McClung, and similar to the odd 

 chromosome of the Coleoptera. 



In various parts of the young male larvae dividing cells were found 

 and the number 23 determined (fig. 269). Turning now to the female 

 larvse to determine the somatic number, the oogonia proved to be more 

 favorable for counting. Twenty-four chromosomes were present in 

 equatorial plates of oogonial mitoses (fig. 270), thus confirming Wil- 

 son's results for the Anasa group of the Hemiptera heteroptera. 



In examining sections of female larvae stained with safranin -gentian- 

 violet, I was surprised to see a very marked polarized or bouquet 

 stage and to find among the loops something resembling the odd chro- 

 mosome of the growing spermatocytes. It was difficult to get a clear 

 view of this body as it lay within the loops. In one section of a 



