628 Staber: The anatomy of Sesban macrocarpa 



cells in width and of irregular shape, they marred the otherwise 



" story-like" appearance. 



The cambium ring separating the woody cylinder from the 

 outer leptome mass, varied from three to seven layers according 

 to the age of the plant (figure 6). The leptome with its long 

 sieve-tubes and companion or cambiform cells, was cut off on its 

 outer edge. The sieve-plates were visible only after being stained 

 with Delaficld's haematoxylin or with methylene blue. Besides 

 the ordinary transverse obhque plates, twin sieve-plates (figure 7), 

 and a number of lateral ones were found (figure 5), This may 

 be peculiar to this particular species, for no mention is made of 

 this point in the various Leguminoseae which hitherto have been 



examined. 



Scattered throughout the leptome portion, in the older stem, 

 especially near the root, were single spindle-shaped cells or groups 

 of them, more or less sclerenchymatous in character. Their outer 

 wall was lignified, whereas their inner more or less gelatinous or* 

 mucilaginous lining consisted of cellulose.* This cellulose lining 

 was quite separate from the wall, as the plant had been in alcohol. 

 There was evidence, in the portion just above the root, that these 



^ 



fibers migrate to the outer edge of the leptome and combine to 

 form the stereome. These cells were most abundant in the root, 

 forming the mechanical tissue in the center in the leptome. 



The stereome, formed of long thick-walled lignified cells; 

 1.807 ^^' ^o"gf with walls 4.6// thick and a lumen of 6.25/^; 

 pectinated to form a tough fiber of considerable strength. In 

 India, 6*. aaileata Pers. is especially cultivated for Its fiber,f from 

 which fishing nets are made. We are told that it is tough and 

 durable, but on account of its shrinkage when wet, is not suitable 

 for ship's cordage. In the younger portions of the stem, the 

 stereome was thln-walled, not being lignified until one reaches a 

 point 22.7 cm. back from the tip, or at 82.8 cm. from the base. 

 After lignification set in, the walls began to thicken (figure 8) 

 and became more rigid. As the circumference of the stem 



*Tschirch, Angewandte Pflanzenanatomie i : 295. Chloriodide of zinc stained 

 the lignified walls yellow, and the cellulose red-violet. 



t Maiden, Some Australian vegetable fibers, Agri. Gaz. of N. S. Wales, Misc. 



Pub. 5 50: 8. 1902. 



