PLATE 9 



EXPLANATION OF FIGURES 



From photographs by the author. Enlargement as in the preceding plate. 

 Photos. 28-38 from sections (28-32 from McClung's preparations), 39-51 from 

 smear-preparations. Photo. 28, Achurum, 29-32 Phrynotettix, 33, 34 Largus cinc- 

 tus, 35-51 Protenor belfragei. 



28 Stage c in Achurum. The unravelling threads clearly shown in the negative. 



29 Early spermatogonial prophase of Phrynotettix, showing the massive chro- 

 matin-bodies just before the spiral thread is evident. 



30 (Fig. 95). At the left, polar view of the coiled threads during the early 

 uncoiling, spermatogonial prophase. 



31 (Fig. 94). The same stage (from a nucleus immediately adjoining in the 

 same section) seen in side-view. 



32 (Fig. 96). Two adjoining nuclei, showing at the left an earlier, and at the 

 right a later stage of the uncoiling of the spireme-threads. The drawings of 

 these and the preceding photo, show threads at other levels as well. 



33 Spermatogonial metaphase of Largus cinctus, 11 chromosomes, including 

 one large pair. The X-chromosome is one of the smaller ones, and can not be dis- 

 tinguished by the eye. 



34 Metaphase of diploid group of the female of the same species, 12 chromo- 

 somes. 



35 (Fig. 1 e, Wilson, '06). Spermatogonial metaphase of Protenor; 13 chromo- 

 somes. 



36 The same. In both these photos, the large ^"-chromosome and the large 

 pair of autosomes are readily distinguishable. 



37-38 Diploid chromosome-groups of the female Protenor, showing the -X"-pair 

 and the large pair of autosomes; 14 chromosomes. 



39 Protenor. Above, a nucleus of the confused stage (g) showing the elongate 

 J-chromosome. Below are three final anaphases of the second division, showing 

 the passage of the undivided ^-chromosome to one pole. 



40-51 Prophase-nuclei of Protenor. Photo. 40 (fig. 120), 41 (fig. 122) 43 (fig. 

 128), 44 (fig. 121), 46 (fig. 129), 47 (fig. 127), 51 (fig. 131). 



448 



