78 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
differ greatly from the corresponding stages in the Acrididae. ‘The 
nuclei are more irregular in shape and the chromatic granules are 
much more abundant and more evenly distributed. ‘The monosome 
occupies a separate vesicle having a complete membrane of its own. 
It is even separated from the rest of the nucleus by a thin layer of 
cytoplasm. ‘The autosomes on the contrary are all enclosed in a com- 
mon membrane not being located in separate vesicles as Otte (:06) 
found in Locusta. ‘The monosome usually appears as an almost - 
homogeneous mass, but when strongly decolorized it exhibits a well 
defined granular structure as in the rest of the nucleus, except that 
the granules are much more closely aggregated. ‘The monosome has 
apparently no constant position in the cell, but may occur at either pole. 
During the prophase (Fig. 16) the chromosomes appear as con- 
torted rod-shaped bodies which later shorten and thicken. In favor- 
ably situated nuclei the monosome can be distinctly seen in a separate 
vesicle (Fig. 16). In the equatorial plate (Fig. L, p. 77, and Plate 2, 
Fig. 18) there are twenty-nine chromosomes, which always lie in a 
single plane. ‘This species is remarkable for the ease with which the 
chromosomes can be counted, as they are usually so well separated 
that there is not the slightest difficulty in distinguishing the individual 
elements. ‘There are always three chromosomes much larger than 
the others; two of these are V-shaped and form a symmetrical pair, 
while the third, a long rod-shaped element is unpaired, being, of 
course, the monosome. A comparison of Figures 16 and 18 shows 
that this is undoubtedly the chromosome which is contained in a 
separate vesicle during the prophase. Its relative size leaves no room 
for doubt on this point. ‘The remaining twenty-six chromosomes can 
be readily grouped in pairs. 
Figure K (p. 77) is a polar view of the metaphase of an epithelial 
cell from the vas deferens. There are probably twenty-nine chro- 
mosomes as in the spermatogonia, but they are so closely crowded 
that I cannot feel sure the count is correct. However, there can be 
no doubt that in these cells, just as in the spermatogonia, there are 
three chromosomes which are much larger than the rest, two of them 
forming a symmetrical pair, while the third is without a correspond- 
ing mate and undoubtedly represents ‘the monosome. 
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