CHROMOSOMES IN COREID HEMIPTEK A. 97 



into the egg among the yolk spheres leaving a train of cytoplasm 

 behind it. It appears as a compact deeply staining rod sur- 

 rounded by a clear area and preceded by an aster (PI. I., d). 

 Tin- ( lear area is probably the "arrhenoid" mentioned by Henking 

 t'<;2) iii hi- account of Pyrrhocoris. The sperm head often ap- 

 pears <"il<<! at the end which points away from the direction 

 of it- mi .\ i -ment. Later it loses its staining power and opens 

 out into .111 oval vesicle (PI. II., a). The clear area and aster 

 are Inn- \\<11 marked though no centrosome is visible in the 

 l>rc|i.ir.iiion. Still later, the vesicle becomes considerably larger 

 ami -in. ill irregular masses of chromatin can be seen in its interior. 

 li i- tin n n.idy for copulation. 



In th mi Miitime, the egg nucleus, formed from the inner group 

 of i litMiii'i-omes of the second polar spindle, has begun to move 

 into tl: -urrounded by a small mass of cytoplasm (PI. I., c). 



Tin i \ topla-m frequently contains one or more yolk sphere-. 

 Tin inn leu- is at t\r>( round in outline and the chromatin i- 

 di-ti ibutt <! in -mall nodules lying chiefly against the iiinli.n 

 membrane. Subsequently it loses its capacity for staining, and 

 apt" >mewhat like the sperm head, but more rounded. It 



i In 11 lii-ins to increase in size, becoming at the same time ir- 

 il.u in -hape and the chromatin once more appears in irregular 

 mass* 



\- tin two pronucki approach each other their cytoplasmic 

 areas lu-e and they come to lie side by side with an amphiaster 

 bet \\ern I'l. II., h; the aster on the upper side of the nuclei 

 was iliaun from the next section). In contact with each pro- 

 nueleu-. may often be seen a large clear vesicle. These probably 

 repie-eni the structures mentioned by Henking as the "descend- 

 ant- "I tin arrhenoids," ;. e., derived from the clear area sur- 

 rounding tin' male pronucleus. In PI. II., b, one of the aster- 

 contains a minute centrosome. The entire amphiaster is prob- 

 abl\ lornu'd under the influence of the male pronucleus, for, in 

 the same egg from which PI. 1 1. .6, was taken, an accessory -perm 

 nui-kii- was found with a very small amphiaster lying in contact 

 with it. The further history of the clear vesicles could not be 

 foll.)\\rd as very few first cleavage figures were found; at a later 

 stagi of (,.[, ulation (PI. II., c) they did not appear. Henking 



