C. A. BARBER 47 



There is little in these Plates which calls for special attention, as the general 

 course agrees with that in grasses and has been sufficiently described in text 

 books. In the cases of Karun seedlings which have been examined (PI. V.), there 

 is an elongation of the plumule axis below the first leaf, similar to that in the 

 wheat, presumably designed to place the young plant clear of its seed-coats and 

 near to the surface of the ground for the purpose of tillering, and I have repro- 

 duced a drawing from Percival's Agricultural Botany to make this clearer. 

 But, in the Karun seedlings, a thickish root is given off from this elongated part 

 of the stem, which I have not seen figured elsewhere. The purpose of this early 

 root formation appears to be obvious enough, namely, to reinforce at the earliest 

 possible moment the small amount of available stored material at the disposal 

 of the young plant. The radicle with its first root has, as usual, a merely 

 temporary existence, or lingers for some time as a minute fibre which can have 

 little effect in aiding the plant in its growth. After this preliminary arrange- 

 ment of the parts of the seedling has been concluded, the plumule develops 

 its leaves in rapid succession and, near their bases, a series of thick adventitious 

 roots are soon produced ; but the seed-coats, with the plug-like sucker, the 

 elongated plumule axis and its first adventitious root, remain attached to the 

 plant for a considerable time, as they have been detected in a Karun seedling 

 already five inches above ground. Different stages in this development are 

 given on Plates IV, V and VI. 



The leaves are formed in one plane, alternately on either side of the stem, 



and the whole young plant may thus be pressed flat with all its parts spread 



out. At a very early stage of development, a bud is formed in the axil of each 



leaf, so that the branches, as well as the leaves, all arise in the same plane. 



The formation of successive leaves, one at a time, has the eft'ect of dividing 



the stem into a series of segments, each provided with one leaf and one bud. 



These segments are usually termed joints, and it is the practice to regard the 



joint as bearing its leaf and bud at its lower end, being thus terminated above 



and below by a leaf, and, when this has withered and fallen, by the sharp ridge 



or leaf scar which completely surrounds the stem. The region where the 



joints are separated is termed the node or knot, as it is usually more or less 



swollen, and the joint as defined above thus becomes the internode. An 



appropriate arrangement of the fibrovascular bundles within the stem has 



meantime taken place, and this can be very well seen in longitudinal sections ; 



namely, while the bundles run parallel with the length of the stem in the 



internode, they form an intricate, Avefted mass at the node, and branches are 



given off to the leaves and roots at this point. This arrangement of the bundles 



takes place very early in the development, and it is thus easier to demonstrate 



