658 Wisconsin Academy of Sciences, Arts, and Letters . 
Figure 22. A'later stage in the second contraction. The nu¬ 
clei in the anther from which this was drawn were 
unusually small. Some cut ends show in the figure. 
Figure 23. The second contraction figure is becoming lost due 
to the separation of the chromosomes from one an¬ 
other due to shortening and thickening. 
Figure 24. A later stage in the shortening and thickening of 
the spirern segments to form the double diakinetic 
chromosomes. 
Figure 25. Early diakinesis. The chromosomes very irregu¬ 
lar in size. 
Plate II. 
Figure 26. A cell in the multipolar spindle stage. 'Note the 
draAvn condition of some of the chromosomes as 
though under tension. 
Figure 27. A cell in which the multipolar spindle is becoming 
bipolar and the chromosomes are being drawn into 
the equatorial plate. Note the distorted appearance 
at the point of the attachment of the spindle threads. 
Figure 28. The heterotypic metaphase stage. 
Figure 29. A polar yiew of the equatorial plate stage. 22 
double heterotypic chromosomes are present. 
Figure 30. Polar view of heterotypic equatorial plate. 24 
chromosomes. 
Figure 31. Late anaphase heterotypic division. The V- 
shaped chromosomes arising from the second longi¬ 
tudinal splitting are to be seen. 
Figure 32. A polar view of an anaphase somewhat earlier 
than that represented in figure 3,1 ! : showing the V- 
shaped chromosomes. 
Figure 33. A partial polar view of the early telophase of the 
heterotypic division. The chromosomes are becom¬ 
ing elongated and knotty. 
Figure 34. A resting nucleus of the heterotypic division. 
Note the lack of a reticulum and the presence of a nu¬ 
cleolus. 
