22 
BULLETIN 1450, U. S. DEPARTMENT OF AGRICULTURE 
occurs in the proaxis. The data in Table 9 show that in shoots 
grown from seeds sown in September there was an average of 14.6 
nonelongated internodes, whereas in shoots grown from seeds which 
were not sown until April there was an average of only 7 internodes 
in the proaxis. 
Table 9 shows that there is also some variation in the number of 
internodes in the elongated part of shoots which have had different 
growing periods, though this variation is very much less than in 
the number of nonelongated internodes. The shoots from seeds 
sown in September had an average of 6.4, while the shoots from 
seeds sown in April had an average of 5.3 elongated internodes in 
the haplocorm and culm. 
On July 15, 1916, 30 fertile shoots were taken at random from a 
meadow of ordinary timothy. The number of elongated internodes 
in these shoots is shown in Table 10. 
Table 10. — Number of elongated internodes per shoot m 30 fertile shoots col- 
lected from an ordinary meadow on July 15, 1916 
Items of comparison 
Number of elongated internodes 
Haplo- 
corm 
Culm 
Total 
19 shoots (63.3 percent) had 
5 shoots (16.6 percent) had- 
4 shoots (13.3 percent) had. 
1 shoot (3.3 percent) had._. 
1 shoot (3.3 percent) had.._ 
The number of elongated internodes in the timothy shoots col- 
lected on July 15, 1916, varied from five to eight. The average num- 
ber of elongated internodes per shoot was 6.1. Similar records 
which have been obtained at different times show that the results 
presented in Table 10 are fairly typical of records that might be 
obtained in any ordinary timothy meadow. 
Fertile shoots having more than seven or eight elongated inter- 
nodes are comparatively rare among those which develop in early 
summer. In the aftermath which grows during midsummer and 
autumn fertile shoots having eight or nine or more elongated inter- 
nodes are common. These fertile shoots having supernumerary 
elongated internodes are often relatively short. Shoots of this 
kind, like the fourth and fifth stems from the left in Plate 4, Z?, 
may perhaps be regarded as gradations between typical fertiTe 
shoots and typical sterile ones. 
RELATIVE LENGTH OF DIFFERENT ELONGATED INTERNODES 
The lowest elongated internode of a normal fertile timothy shoot 
is the shortest, and each succeeding internode has a greater length 
than the one below it (26, p. 135-137). This is illustrated by the 
record in Table 11 of the average lengths of the internodes of 
eight fertile timothy shoots collected from a meadow on July 15, 
1916. Each shoot had one enlarged internode in the haplocorm and 
five elongated internodes in the culm. The internodes are num- 
bered in order from the lowest to the highest. The average length 
