OF THE GERM CELLS OF METAZoA. 



195 



nucleoli (K 2), which are not closely apposed ; the true nucleolus (N) is much larger. 

 In the rest stage the chromatin nucleoli are usually widely separated from one another, 

 and on account of their small size are difficult to discover. In the growth period they 

 do not stain bright red with the saffranine-gentian violet stain of Hermann, but deep 

 violet, even on excellently stained preparations. Such a staining reaction as this I have 

 not found for the chromatin nucleoli of other Hemiptera, for in all the other forms 

 examined the chromatin nucleoli take the red saffranine stain intensely even while the 

 chromosomes have taken the violet stain (in the rest stage). Perhaps in Hygotrechus 

 the chromatin nucleoli differ chemically less from the chromosomes than in the other 

 Hemiptera, and undergo in the growth period changes parallel to those of the chromo- 

 somes. 



Pole views of the monaster stage of the first maturation division (Fig. 231) show 

 always exactly eleven chromatin elements. On account of the number in the spermato- 

 gonia (twenty), I would interpret these as nine bivalent chromosomes, and two univalent 

 chromatin nucleoli which are not combined into one bivalent one. This is very probable, 

 since the two univalent chromatin nucleoli are often widely separated in the growth 

 period ; and on lateral views of the monaster stage of the first maturation division, there 

 are found two bodies which are spherical and not dumbbell-shaped. On no lateral view 

 of this monaster stage could I see all the nine chromosomes clearly ; but in one case I saw 

 eight of tbeni, all clearly dumbbell-shaped (bipartite), so that probably all nine arc 

 bivalent. The first maturation division is reductional, as in the other Hemiptera. 



40. Limnotreehus marginatum Say 



Two testes of this species were studied. 



There were no spermatogonia monaster stages present, and I could not determine the 

 relations of the' chromatin nucleoli in the rest stage of these cells. 



In the rest stage of the spermatocyte (PI. V, Fig. 232) is found a large true nucleo- 

 lus (iV), and separated from it, usually close to the nuclear membrane, a rounded 

 chromatin nucleolus (N. #). 



Pole views of the first maturation monaster (Fig. 233) show eleven chromatin ele- 

 ments; sometimes one appears much smaller than the others, and it may represent the 

 chromatin nucleolus. 



N~AUCOKID.fi. 



41. Pelocoris femorata Pal. Beau v. 



Fourteen testes of this species were studied from adult and half-grown individuals 

 of different seasons of the year. There were an abundance of rest stages of spermato- 

 gonia and of spermatocytes in the growth period, but no maturation mitoses present. 



