PLATE 8 



EXPLANATION OF FIGURES 



148 Asilus lecythus, haploid, metaphase, second spermatocyte. 



149 Asilus notatus, diploid, metaphase, spermatogonium. 



150 Same haploid, metaphase, second spermatocyte. 



151 Leptogaster badius, diploid, spermatogonium, metaphase. 



152 Same, haploid, metaphase, second spermatocyte. 



153 Erax rufibarbis, diploid, metaphase, spermatogonium. 



154 Same, haploid, second spermatocyte. 



155 Dasyllis thoracica, diploid, spermatogonium, prophase, entire nucleus. 



156 Same, metaphase. 



157 Same, haploid, metaphase, first spermatocyte. 



158 Same, haploid, second spermatocyte. 



159, 160 and 161 Deromyia winthemi, diploid, metaphase, spermatogonia. 



162 Same, haploid, metaphase, first spermatocyte; note X and Y going to 

 opposite poles. 



163 Same, haploid, second spermatocyte, Y-containing group. 



164 Same, X-containing group. 



165 Culex pipiens, diploid, early prophase, ovarian cell, entire nucleus. 

 Three pairs of chromosomes, note polarization. 



166, 167 and 168 Same, diploid, spermatogonia, metaphase. 



169 Same, anaphase, side view showing division of chromosomes and separa- 

 tion of daughter halves. 



170 Same, earlier stage, side view showing manner of division; only three 

 of the chromosomes are represented. 



171 Same, same stage as 169; only two pairs of chromosomes represented. 



278 



