OF THE GERM CELLS OF METAZOA. 193 



chromosomes present, four of which are always grouped together to form a particular 

 group. 



The metakinesis halves each of the fourteen bivalent chromosomes transversely 

 (reduction division, Figs. 217, 218), but the four which together form the group that has 

 been described divide later than the others, as can be seen from the figures given ; and it 

 is at this metaphase that this group of four can be most easily recognized. Such a group 

 of four closely united bivalent chromosomes has not been found by me in any other 

 Hemipteron. 



36. Prionidus cristatus Linn. 



Four testes of this species were studied. 



In the rest stage of the sperm atogonium there are apparently five chrornatin uucleoli 

 (N. 2, Figs. 220-222, PI. V), two of which are generally considerably larger than the 

 others, and some or all of which may be attached to the true nucleolus (N, Figs. 221, 

 222). But it is difficult to be sure of the exact number, for sometimes not more than 

 four can be seen (Fig. 221). 



In the spermatogonic monaster on pole views (Figs. 223, 224) are seen twenty-six 

 chromatin elements, three of which (N. 2} are always much smaller and (by analogy 

 with the other species of the Reduviidce) would probably represent the three small 

 chromatin nucleoli of the preceding rest stage. Two of the twenty-six chromatin ele- 

 ments are elongate in form and much larger than the others ; these may be chromosomes 

 (which would be more probable), or they might represent the large chromatin nucleoli of 

 the rest stage of the spermatogonium. If there are really five chromatin nucleoli in the 

 spermatogonia, then there would be these five elements and twenty-one chromosomes 

 present in the spermatogonic mitosis. In five pole views I could count exactly twenty- 

 six chromatin elements, in two there were either twenty-six or twenty-seven, and in one 

 either twenty-four or twenty-five ; but in all these cases three particularly small and 

 two particularly large elements could be distinguished. 



In the rest stage of the spermatocyte (Fig. 225) are found four chromatin uucleoli 

 {N. 2} attached to the true nucleolus (N). One of these is longer than the others and 

 rod-shaped, and may represent the two larger chromatin nucleoli of the spermatogonium 

 joined into one bivalent one ; the three smaller ones may appear rounded or slightly 

 elongate, and these may represent the three small chromatin nucleoli of the spermato- 

 gonium ; occasionally two of the small ones are apposed together. 



There were no maturation mitoses on my preparations (from adults taken in the 

 month of September). 



