488 Alice M. Boring 



the stainable chromatin is aggregated into one body, there is no chro- 

 matin left elsewhere. The situation is much clearer if looked at 

 from Conklin's point of view ('02) : although the nucleus in the 

 rest stage does not take basic stains, it still contains chromatin in 

 the form of oxychromatin; this has the power of changing into 

 basichromatin to form the chromosomes for division. The basi- 

 chromatin masses of the rest stage, with the exception of the odd 

 chromosome, which here again shows its individuality by a differ- 

 ence in behavior, are apparently rejected substances, which dis- 

 appear without playing any further role in karyokinesis. 



In the prophase, the odd chromosome lies close to the nuclear 

 membrane as in the forms previously studied, and in the metaphase 

 it has a somewhat eccentric position (Fig. 70). The chromosomes 

 here are so nearly of the same size that it is impossible to trace any 

 individuals from cell to cell; but the odd chromosome, by virtue of 

 its position and its univalence, can be followed until the second 

 spermatocytes are formed. Figs. 71 to 73 show its varying behav- 

 ior in metaphase; it may either follow or precede the other chromo- 

 somes to the pole. This fact is shown also by the two anaphase 

 figures, 74 and 75. The second spermatocyte equatorial plates 

 show the two numbers of chromosomes 1 1 and 10 (Figs. 76 and 77), 

 but the odd chromosome can no longer be distinguished from the 

 others, either in metaphase (Fig. 78) or anaphase (Fig. 79). In all 

 the spermatids (Fig. 80), there appears one large body {n) taking 

 the basic stains, probably analogous to the body in the beetle sper- 

 matids called a chromatin nucleolus by Stevens ('06b). It is 

 impossible to decide whether the odd chromosome in half the sper- 

 matids keeps its individuality as was observed in Entilia and Van- 

 duzea, for all the chromatin stains deeply and in some stages is 

 broken up into many separate masses (Fig. 80). 



Ceresa bubalus 



The only external difference between this species and the fore- 

 going one is its greater size and the different angle of the prothor- 

 acic protuberances. The only difference in the spermatogenesis 

 as can be seen by Figs. 81 to 92, is that the mass of rejected chro- 

 matin is not so conspicuous. In the bouquet stage (Fig. 81), the 



