678 C. E. McCLUNG 



at the synaptic end, which Hes toward the spindle axis. In the 

 anaphase the daughter chromosomes go to the pole as simple Vs 

 (figs. 5, 6, 7 and 35). 



(3) Annular chromosomes dividing transversely lie extended 

 parallel to the spindle axis and have the fiber attachment at the 

 middle of the chromosome or near the middle. The anaphase 

 chromosomes are double Vs (fig. 67). 



It is necessary also to consider those other chromosomes with 

 median or subterminal attachment of fibers which do not take 

 on the form of rings. For our present purpose it is sufficient 

 to note that they differ only in the degree of their chromatid 

 movements from the rings and in the late prophase are indis- 

 tinguishable from them. The chromosomes shown in figures 64 

 b, c, d and h may have been rings like figure 64 g or their parts 

 may never have come into the ring association. The points of 

 interest to note here is that such chromosomes, whether rings or 

 not, always show in the anaphase double V-shaped forms. 



CHROMOSOMES OF SECOND SPERMATOCYTE METAPHASE 



The conditions of most interest for this study with regard to 

 the second spermatocyte reveal themselves fully only in the meta- 

 phase condition, but it is necessary to note briefly some of the 

 earlier phases. Of course, so far as the accessory chromosome 

 is concerned, it is found in but half this generation of cells, but, 

 since this does not otherwise influence the chromosome relations, 

 it will not be necessary to consider the matter further at this time. 

 The distinction between the first spermatocyte telophase and the 

 second spermatocyte prophase cannot be sharply drawn, for the 

 reason that in some species there is no loss of form by the chromo- 

 somes, and the only indication of the prophase condition is the 

 presence of the chromosomal group within a nuclear membrane 

 and the forming archoplasmic spindle. This period is very 

 brief and it is possible to find exceptionally in one cyst first sper- 

 matocyte telophases and second spermatocyte metaphases. 



A second spermatocyte metaphase figure distinguishes itself 

 at once from that of either of the two preceding cell generations, 



