290 Wisconsin Academy of Sciences, Arts, and Letters . 
much coiled and twisted thread is finally evolved (figs. 13, 14, 15, 
17). Sharp (’13) holds that the chromatic material condenses 
along a very irregular region around the open spaces and cavities. 
It appears from a most careful study of my preparations that the 
granules, which are present in the prophasic reticulate bands, be¬ 
come condensed along certain strands or lamellae to form ir¬ 
regular platelets. These platelets are placed more or less, at right 
angles to the long axis of the bands. On examining figure 13 
again in detail, such condensations may be seen with many of the 
collections or irregular platelets more or less at right angles to 
the length of each band. This is especially observable at the 
bottom of the figure. Linin threads or lamellae may still be seen 
connecting them in various places. 
The chromatin granules collect on the periphery of the alveoli 
of the bands in such a manner as to form a more or less zigzag 
arrangement across the bands. This would also account for the 
arrangement of the platelets. By the dissolution or withdrawal 
of the free linin portions, the platelets would thus be arranged 
in a zigzag spiral-like line or thread. This final arrangement is 
indicated in figure 14. In figure 15 the spiral arrangement of 
the individual bands is very distinct. In the upper part of the 
nucleus transformation has not so far progressed, the bands being 
still quite reticulate. Figure 16 represents a nucleus in which 
most of the bands have been cut transversely. Irregular chro¬ 
matin platelets are quite distinct at various places in the nucleus. 
Figure 17 represents a nucleus in which all the bands have been 
transformed into threads. The whole thread in its entire length 
is long, slender, spirally coiled, and much eonvulated in the 
nuclear cavity. From my observations I am convinced that there 
are breaks in this thread and that no continuous spirem is formed. 
Sharp (T3) describes similar zigzag bands in the prophases 
of Yicia, points out that most authors have omitted these stages 
from their accounts, and holds that these stages are of the greatest 
importance in interpreting the splitting of the chromosomes. 
Sharp (’205) also describes like stages for Tradescantia. Such 
stages are exceedingly abundant in Podophyllum and are omitted 
by Fraser and Snell (’ll), and as Sharp points out, are not de¬ 
scribed by Digby (’19) for Osmunda. Lundegard (’09, ’10a, 
’12a, 5, e), also fails to describe such zigzag threads for Yicia. 
Although I have searched carefully and have followed in detail 
the formation of these zigzag bands, I have never found any evi- 
