FLOWEES AND BOLLS OF PIMA AND ACALA COTTON 9 
resulting in higher probable errors. In 1925, however, data' were 
obtained on a larger number of squares, and significantly longer 
periods on the outer nodes are found for nodes 3 and 4, respectively, 
compared with node 2 in the interval from June 8 to 17; for node 4 
compared with nodes 2 and 3 in the interval from July 8 to 17; for 
node 4 compared with node 1 in the following interval; and for 
node 4 compared with node 2 in the last interval. From these data 
it seems apparent that the squares on outer nodes of the fruiting 
branches of Acala generally require a longer time to reach the flower- 
ing stage than those on inner nodes, but this lengthening of the period 
on outer nodes is not so great nor so constant as in the Pima variety. 
As shown in Table 4, squares on the second nodes of the fruiting 
branches of both Pima and Acala usually reached the flowering stage 
in a shorter time than did those on node 1, the same tendency being 
apparent in both seasons. That the square periods did not lengthen 
more consistently may be owing to other factors not yet recognized, 
though the general tendencies are apparent. 
The average number of days required for squares of both varieties 
throughout the seasons of 1924 and 1925 to develop into flowers on 
specific nodes of the fruiting branches is given in Table 5, which 
also contains the average square period for both years. The table is 
a summary of the data presented in Table 4. 
Table 5. — Average number of days required for squares throughout the seasons 
of 1924 and 1925 to develop into flowers on specific nodes of fruiting branches 
Pima 
Acala 
Season and node of fruiting branch 
Number 
of squares 
Average 
square period 
(days) 
Number 
of squares 
Average 
square period 
(days) 
Season of 1924: 
Node 1 
288 
185 
104 
84 
33. 076=fcO. 071 
32. 400± .089 
33. 635± . 112 
34. 500± . 146 
78 
48 
38 
20 
28. 103±0. 241 
Node 2 
27. 687± . 195 
Node3 
28. 579d= .251 
28. 600± .328 
All nodes - - 
661 
33. 156± . 050 
184 
28. 147± . 088 
Season of 1925: 
Node 1 - _ 
332 
255 
164 
138 
33. 057± .076 
32. 082± .078 
33. 640± . 129 
35.065± .210 
262 
248 
214 
132 
29. 179± . 118 
Node 2 
28. 746± .111 
Node 3 
28. 963± .106 
Nodes4tolast - .. . 
30. 417± . 179 
All nodes 
889 
33.197+ .058 
856 
29. 190± .063 
Significantly longer periods are shown for the outer nodes of Pima 
in both years, though not for the Acala in 1924. In 1925 the fourth- 
to-last nodes represent the only case where the outer nodes have 
a significantly longer period than any of the three preceding nodes. 
In both varieties the squares produced on the first nodes each season 
required a longer period to develop than those on the second nodes, 
and after the first and second nodes the squares on the branches of 
both varieties required increasingly longer periods as they progressed 
outward. 
The average period required for any square to develop, regardless of 
its position on a fruiting branch, was found to be slightly over 33 days 
23914°— 27— 2 
