200 
GENETICS: J. BELLING 
Proc. N. A. S. 
drawn with the camera. Of these 31 clones, 22 showed nine dyads or 
bivalents, which split into 9 + 9 at the first division (fig. 1) ; 3 clones had 
a total of 18 single chromosomes (or 9 bivalents), which divided at the 
first division into 8 + 10, or other unequal numbers, not commonly into 
9 + 9 ; 5 clones were probably completely or nearly triploid, and irregular 
in their first division, resembling in this the triploid mulberries of Osawa, 5 
and like them showing a smaller number of chromosomes after the first 
division than the triple number (in these cases, 24 to 26 instead of 27) ; 
while one clone was regularly triploid, showing nine triads at the prophase 
and first metaphase, and a total of 27 chromosomes after the first division. 
This regularly triploid clone was obtained from Thorburn, New York, 
in 1920, under the name "Gladiator." It differed conspicuously from 
other Cannas with more than 18 single chromosomes, in its smaller flowers 
and lesser size, resembling in these the ordinary diploid Cannas. Thirty- 
two pollen-mother-cells were drawn with the camera. In 18 of these 
pollen-mother-cells, the total number of chromosomes could be accurately 
counted, and was 27. In the 3 other cases where the total number could 
be counted, some chromosomes seemed to be missing, for the totals were 
25, 25, and 24. (In 3 pollen-mother-cells showing the anaphase of the 
first division, or the metaphase of the second, only one group could be 
accurately counted, because of the slanting position of the other. In 
the 8 remaining prophase or metaphase figures, not all the trivalent chro- 
mosomes could be distinguised from the bivalents or univalents into 
which they had divided, or from which they were composed.) 
Nine of the cells showed clearly how many chromosomes went to one 
pole and how many to the other after the first division. 
Chromosome 
partition 
18 + 9 
17 + 10 
16 + 11 
15 + 12 
14 + 13 
Nos. of cells 
found 
0 
1 
2 
2 
4 
Calculated on random 
distribution 
0.04 
0.3 
1.3 
3.0 
4.4 
(In the triploid Datura the chromosomes have been accurately counted 
in 64 pollen-mother-cells after the first division, and the distribution 
corresponds with a random one.) 
Three of the early anaphase plates showed how the triads divided. 
Taking for "up" the upper side of the camera drawing, which was a random 
position, we have for the position of the two's with regard to the equator 
(fig. 2, Nos. 4 and 5) : 
