COURSE OF THE BUNDLES IN THE STEM. 



273 



arranged crosswise, two larger and two smaller, the similar ones being opposite one 

 another. A few layers of cells below the epidermis a circle of eight to ten small 

 bundles is found, which run perpendicularly and separately through the internode. 



In the short thick stem of Stratiotes aloides^ the bundles — all of which descend 

 from the leaves — unite 'after numerous anastomoses to one central bundle and eight 



Fig. 123. — Fotamogeton pectinatus; end of the shoot (40). Thick median section) cleared with potasli, 

 parallel in the lower part to the median planes of the two rows of leaves ; higher up, from leaf 5 onwards, 

 this plane has rotated through almost go". Successive leaves numbered successively 1—6 ; v the opposite 

 sheathing part belonging to the correspondingly numbered leaf; s a sguamtda intravaginalis of leaf 3. 

 In the middle is plainly seen the vascular portion of the sympodium of vascular bundles ; the upper- 

 most bundle, which is clearly seen, goes to leaf 6 (which lies at the back of the section) ; that which goes 

 to 5 is cut transversely, since 5 was turned towards the observer, owing to the above-noted rotation. In 

 the axils of each of the leaves (up to g) an axillary bud is plainly seen. That belonging to leaf 2 lies deep 

 in the section ; its parts are indicated by k, and the vascular bundle which enters it by * + . That belonging 

 to leaf 3 is still small ; but the development of the first vascular bundle which enters it is beginning in the 

 angle where the bundle 3+ (which runs into leaf 3) unites in the node with that which comes from 4. In 

 the cixil of leaf i is a strongly-developed axillary shoot ; «i and 7/2 its scale leaves, l\ and /2 its two first foliage 

 leaves ; the vascular bundle which enters h is just beginning to be developed. In the axil of tn a secondary 

 axillary shoot is appearing ; its first vascular bundle is beginning at^ 



or nine peripheral ones, 

 the internodes.' 



In the thin stolons these bundles run perpendicularly through 



* Rohrbachj /. c. p. 94. 

 T 



