the Embryo and Seedling in the Gramineae . 
215 
emerges from it. The first foliage leaf of the plant is the second in order 
on the axis, for the first is reduced to a mere sheath. 
Two distinct bundles enter the stalk of the cotyledon from the sucker. 1 
The stalk is inserted rather above than below the junction of sheath with 
axis. There is no true lower sheath. In three seedlings the upper bundle 
P runs a little way into the upper sheath before it turns down to join the 
axis. In the remaining seedling, the youngest, P runs up from the stalk, 
and continues its course through the sheath into the axis. The second 
bundle, P', commonly enters the axis from the stalk below the apparent 
insertion. Since P and P' enter the stele from opposite sides, one or other 
of them must skirt it for some distance 
before turning in. 
The stele of the hypocotyl is cut so 
obliquely in the three older seedlings, that 
its structure cannot be deciphered. In the 
youngest seedling, the traces settle down to 
three endarch bundles, which seem to corre¬ 
spond in position to the midrib and lateral 
bundles of the second leaf. They are 
separated by three rays of medullary tissue, 
forming angles of about 120° with each 
other. P enters by one of the two rays 
which border the midrib of the second leaf, 
and P ' by the other. The third ray re¬ 
mains clear. Below this level the stele of 
this seedling too is bent, and the sections 
of it hopelessly oblique. Apparently there 
would be five bundles at the top of the 
hypocotyl, as in Renealmia. 
Text-fig. 34. Brachychilum Hors- 
fieldii, O. G. Petersen. Outlines of 
seedling, life-size and enlarged. 
Brachychilum Horsfieldii , O. G. Peter¬ 
sen. Preparations were made from five 
seedlings by one of us, including complete series through the cotyledonary 
sheath in four of them. The cotyledon is inserted partly on the sheath 
and partly on the axis as in Alpinia . The first leaf is reduced to a mere 
sheath (Text-fig. 34). 
There are two distinct bundles in the apex of the cotyledon, and they 
run side by side through the stalk into the axis. In three seedlings neither 
bundle enters the sheath at all; in the fourth, one trace (P) lies rather 
above the other, and it curves upwards into the base of the sheath, just 
entering it before turning back into the axis. The short upper sheath, 
1 For apparently mesarch structure of stalk-bundles in Alpinia , Brachychilum, and Roscoca, see 
E. M. Berridge in Ann. of Bot., vol. xxiv, p. 485, 1910. 
