76 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
In the metaphase (Fig. G, p. 74) twenty-three chromosomes can be 
distinguished in the equatorial plate and, as in all the preceding species, 
the autosomes can be readily paired. 
F. Stenobothrus curtipennis. 
In this species the elements of the testis are smaller than in Dis- 
sosteira, but larger than in Melanoplus. ‘The apical cell is always 
present at the distal end of the follicle and is surrounded by a single 
layer of primary spermatogonia. In the cytoplasm on one side of the 
nucleus is a mass of material staining deeply with Bordeaux, but it 
is more homogeneous and less distinctly granular than in Dissosteira. 
No granules staining with hematoxylin are present. 
The spermatogonia are much as in Dissosteira, but stain more 
deeply owing to the relatively greater amount of chromatic material. 
The nucleus is also much more irregular in shape than in Dissos- 
teira. ‘This is well shown in the prophase (Plate 1, Fig. 17, Plate 2, 
Fig. 21), where the large vesicular nucleus is more easily distinguisha- 
ble from the surrounding cytoplasm. ‘The asters first appear in a 
deep depression on the distal side of the nucleus. At the center of 
each aster is a minute centrosome. In the metaphase there are 
seventeen chromosomes in the equatorial plate, which differ more in 
size than in the preceding species and thus can be more easily grouped 
in pairs. In Figures J and J can be seen three pairs of very large auto- 
somes (1, 2 and 3), which differ not only in size but in shape. ‘The 
chromosomes of one of the three larger pairs always have the mantle 
fibers attached to their middle, the two equally long arms projecting 
away from the spindle in the form of a letter U or letter V. In the 
case of the other two large pairs, the mantle fibers are attached not 
at the middle but nearer one end of the chromosome, the projecting 
arms thus being of unequal length. ‘The next smaller chromosome 
(4) is the monosome. Between the monosome and the next smaller 
chromosomes there is a distinct break in the series. The ten smaller 
autosomes can easily be grouped in five pairs (5, 6, 7, 8, and 9), which — 
constitute a nicely graded series. 
Of all the species studied, Stenobothrus shows most clearly the 
paired relation of the autosomes. However sceptical one may be 
about this in the case of the other species described, there can be no 
doubt that in Stenobothrus there are always, with the exception of the 
monosome, two chromosomes of each size. 
