3 82 



Edmund B. Wilson, 



somes agrees with that of Lygaeus, being 14 in the spermatogonia, 

 eight in the first spermatocyte-division, and seven in the second, 

 and their grouping is similar (Figs. 3, 7), save that in Brochymena, 

 alone among all the forms, the small idiochromosome frequently 

 lies in the outer ring (Fig. 7&). Podisus differs only in the 

 fact that the numbers are respectively 9 and 8 (Figs. 3/, /, ra), 

 while the spermatogonial number is 16 instead of 14 (Fig. 5^). 

 Trichopepla is a puzzling case which I have not yet fully cleared 

 up. The daughter-groups of the second division show 7 chromo- 



C 



* 



t 



FIG. 4. 



Nezara. a, b, metaphase-groups, first division; c, metaphase-group, second division; d, entire chro- 

 mosome-group, second division, in side view, showing equal division (three chromosome-pairs from a 

 lower level of the spindle shown at the right); e, f, duplicate sister chromosome-groups, anaphase of 

 second division, from the same spindle; g, h, spermatogonial metaphase-groups. 



somes each (Fig. Jq, r), the idiochromosomes being well differ- 

 entiated. The first division, however, agrees with Montgomery's 

 description in showing either 9 (Fig. 70) or 8, the smallest chro- 

 mosome being in the latter case wanting. 



The conditions in Nezara are of particular interest from a 

 comparative point of view in that the idiocbromosomes are of equal 



