3H 
Floating- Roots of Sesbania aculeata , Pers. 
EXPLANATION OF FIGURES IN PLATE XVII. 
Illustrating Dr. D. H. Scott’s and Mr. H. Wager’s paper on the Floating-Roots of 
Sesbania aculeata , Pers. 
Fig. i. Portion of a transverse section of a young root, showing the first divisions 
of the inner cortical cells to form the phellogen. /, primary lacunar tissue of cortex. 
ph , phellogen. e, endodermis. pc, pericambium. ph. f bait-fibres of a phloem 
group, x 360. The shaded cells in the cortex are tannin-sacs. 
Fig. 2. Similar section from a much older root. The phellogen is now in full 
activity, fl, youngest part of floating tissue, t, tannin-sac. Other letters as 
before. >^360. 
Fig. 3. Transverse section of a young tetrarch root. One or two layers of the 
floating tissue have already been formed. The tom primary cortex is shown 
outside the floating tissue. Letters as before, x 1 20. 
Fig. 4. Section of an old root, showing a portion of the floating tissue in 
position. Letters as before, x 200. 
