Amitosis in the Ovary of Protenor belfragei and a Study of the Chromatin A'ueleolus. 215 
the exceedingly small chromatic body which is sometimes present in 
the ovarian cells as well as in the spermatocytes can be interpreted as 
the nucleolus of these cells. This small chromatic body is most distinctly 
demonstrated in the ovarian nucleus of photos 33 and 34, in one of 
the five nuclei of photo 47, and in photos 52 and 54. 
In the spermatocytes it is clearly present in photo 38 and it is also 
seen although less distinctly in some of the other nuclei. It is interesting 
to note that in many of these cases the relation in size between this small 
body and the nucleolus is exactly the same as between the large and small 
nucleoli which are so frequently found in Euschistus. Compare for exam- 
ple photos 52 and 54 with photos 2 and 6 of Foot and Strobell (1909). 
Montgomery (1901) in his figs. 118 and 124 demonstrates two small 
chromatic bodies. He finds them both in the spermatogonia and sperma- 
tocytes and he interpreted them in 1901 as chromatin nucleoli and in 1906 
as diplosomes. They are probably structures similar to those we have 
demonstrated, though as a rule, we find only one. Photo 33 is an excep- 
tion as two or even three are seen. The inconstancy in their size, 
number, and form makes their identification as two of the somatic 
chromosomes very doubtful, and questions whether the chromatic bodies 
demonstrated by us are the same structures as those figured by Mont- 
gomery. In the germinal vesicles we have found no chromatin nucleolus 
and further, we have not been able to demonstrate the large achromatic 
nucleolus we demonstrated in Euschistus variolarius and found also in 
Anasa tristis. 
But in view of the great variability of such structures we are by 
no means prepared to say that they are never present in Protenor. The 
only evidence we have that they may sometimes be found in later stages 
is the fact that they can be demonstrated in some of the younger nuclei, 
photos 58 — 61 and 63, plate XVIII, and further, in sections weoccasionally 
find a large chromatin nucleolus in the germinal vesicles at about the 
stage of development of those shown in photos 75 — 81. From the point 
of view of variability we may record the fact that in rare cases we have 
found in Euschistus variolarius an enormous chromatic nucleolus instead 
of the large achromatic nucleolus. These cases give an impression that 
the achromatic nucleolus is impregnated with a deeply staining substance, 
but as such cases have been found only in sections, we cannot be sure 
that fixation is not at least in part responsible. 
In this connection certain variations in the large nucleolus of Allo- 
lobophora foetida may be of interest. Although we demonstrated in 1905 
that this large nucleolus may remain intact after the chromosome are 
