498 
Max Morse 
presenting tke ordinary chromosomes begiu to tbicken (fig. 37) and 
for a time it is tbe most couspicuous structure in tbe uucleus. Its 
bistorv from now on until tbe end of tbe mitosis is not as clear as 
heretofo^e, owing to tbe fact tbat all of tbe cbromosomes now 
assume tbe same form and tbe writer bas been unable to recognize 
it after such a stage as is shown in figure 39. It unquestionably 
participates in tbe quadripartite appearance of the ordinary cbromo- 
somes for all of tbe cbromosomes of tbis stage are of tbis sbape. In 
the metaphase (tigs. 40, 41 and 43), all of tbe chromosomes are alike 
duinb-bell shaped. Counts of the cbromosomes lying in tbe metaphase 
plate may be made with the greatest ease, for tbe cbromosomes 
seldom touch eaeb other (fig. 42). Some cells sbow sixteen (fig. 42 r) 
while otbers sbow seventeen (fig. 42 /), the forraer evidently being 
those in wbicb the odd ckromosome is absent, tbe latter tbose in 
wbicb it is present. Theoreticallv, cells coutaining sixteen and tbose 
coutainiug seventeen should occur in equal numbers. The writer 
bas counted tbe cbromosomes in one hundred cells in metaphase of 
tbe second division, taken at random and of tbese, fifty-four presented 
sixteen cbromosomes and tbe other forty-six sbowed seventeen. 
Figure 45 shows two sister cells in telophase wbich exhibit no 
chromosome-nucleolus, while such a body is present in botb of tbe 
sister nuclei shown in figure 46. Observations were made on Auer- 
bach material witb positive results to make sure tbat tbese are 
cbromatin bodies and not plastin structures and tbis is clearly evident 
in such material. Cells coutaining such a body and those without it 
occur in approximately equal numbers in the cysts. Tbe fate of tbe 
odd cbromosome will be traced after a brief consideration of tbe 
plasmosome. 
c) Tbe plasmosome. Tbe plasmosome is not to be seen in tbe 
cells of tbe secondary spermatocyte previous to the anapbase (fig. 44) 
where it lies at tbe edge of tbe spindle. It stains faintly during 
tbese stages, increasing in intensity of coloring as time goes on. 
During tbe telophase (figs. 45 and 46) it is much more conspicnous, 
showing a vacuole within it. As in other mitoses, it is never secn 
within tbe uucleus wben tbe nuclear wall bas been formed in tbe 
telophase, but always lies out in tbe cytoplasm. It does not frag- 
ment until a mucb later stage, as will be described. Tbe origin of 
tbe plasmosome of tbis division cannot be given, but its fate is 
read i ly seen. 
