104 CHROMOSOMES IN THE SPERMATOGENESIS OF THE HEMIPTERA HETEROPTERA. 



in which case the smtiller diplosome is hidden from view by the larger, or 9 (Fig. 36) 

 when one of the diplosomes is seen below the other. The 7 autosomes divide equa- 

 tionally, but the diplosomes without dividing pass into opposite daughter cells (sper- 

 matids). Each spermatid (Fig. 37) shows on pole view 8 chromosomes, a circle of 

 7 autosomes around a central diplosome ; half the spermatids receive the larger 

 diplosome, and half the smaller. 



Literahire. — I had originally erroneously stated there were 18 chromosomes in 

 the spermatogonia, and had failed to note that the diplosomes enter separately into 

 the equatorial plate of the first maturation monaster. 



6. Nezara hilaris Say. 



Spermatogonic Divisions. — In the equatorial plate (Plate IX, Fig. 38) there are 14 

 chromosomes ; 12 are autosomes that compose 6 pairs of gradated volumes {A, a-F, f), 

 while the two smallest are apparently not quite equal in volume (Z)i, di) and are the 

 diplosomes. 



Growtli Period. — The diplosomes conjugate and remain in close contact during 

 the growth period (Fig. 39, Di, di). From the late synapsis stage on each appears 

 plainly constricted, which is probably to be interpreted as a longitudinal splitting. 



There were no later stages upon my slides. 



Literature. — In the former paper (19016) I was mistaken in supposing thereto 

 be 16 chromosomes in the spermatogonia. Wilson (1905a) presents observations upon 

 the later stages, and shows that the diplosomes divide separately and equationally 

 in the first maturation division, but conjugate and separate reductionally in the 

 second ; but he is mistaken in saying that the diplosomes are of equal volume. 



7. Brochymena sp. 



SpermcUogoiiic Division. — Pole views of the equatorial plate (Plate IX, Figs. 40, 

 41) show 14 chromosomes, of which 12 {A, a-F,f) form 6 pairs of graduated volumes 

 in which the two members of each paii- are approximately equal in form and volume ; 

 while the remaining pair consists of one element (Di) that is the smallest of all and 

 of another {di) that is constricted and is larger than either of the components of the 

 autosome pair, F, f. 



Grouih Period. — The twelve autosomes unite to form. 6 bivalent ones. The 

 diplosomes also conjugate, and each becomes constricted as in Euschisfus vuriolarius. 



First Maturation Division. — Late in the prophase the diplosomes separate and 

 enter into the chromosomal plate aj^art from each other (Di, di, Figs. 42, 43). These 

 divide equationally, but the 6 bivalent autosomes reductionally. 



