Staber : The anatomy of Sesban macrocarpa 631 



The structure of the root next claims our attention. The 

 plant examined had a well-developed primary root with a thick 

 mass of secondary ones, upon which nodules had formed. Exami- 

 nation of the root of a seedling showed it to be of the radial 

 tetrarch type, the bundles enclosed by pericambial and endodermal 

 layers. As in most Papilionaceae, there was a common meriste- 

 matic zone extending across the plerome and periderm areas.* An 

 older root showed the bundles meeting in the center, and the 



F 



leptome pushed out until it formed a ring about the central woody 

 cylinder. The bundles were formed of libriform cells and pitted 

 ducts, but there were no ring ducts. Many of the ducts had cross- 

 walls formed of a fan-like radiating structuref or of ladder-like 

 construction. In this respect the root differed from the stem and 

 from Leguminosae in general, that is, in having simple openings 

 beUveen ducts, as mentioned at the beginning. The medullary 

 rays, too, showed some variation, in being from one to three cells 

 wide. On, entering the leptome area, they broadened consider- 

 ably, becoming wedge-shaped. As in the stem, the cells were 

 filled with starch. The leptome was well developed. The cells 

 contained starch, and were interrupted in a few places by tannin 

 ducts. Scattered in the leptome was a great number of stereome 

 fibers, having lignified walls and a cellulose lining, being of the 

 same kind as occurred in the stem above the root (figure 9). 

 The libriform cells, throughout the center and tojvards the edge 

 of the hadrome, were of like construction. We are told that the 

 appearance of this " 3d membrane " among libriform cells is an 

 irregular one,;]; " They showed most prominently after treatment 

 with chlor-iodide of zinc, the lignified walls becoming yellow, and 

 the cellulose lining or '' 3d membrane" (Tschirch), a red-violet. 



The leaf (figure 10) showed the usual dorsi-ventral structure. 

 Weyland § summed up the characteristics in his researches on the 

 Galegeae, one of which was Sesban. Examination of the leaf oi 

 S. macrocarpa showed an agreement in all the details* The 

 stomata appeared on both sides of the leaf, but were somewhat 



*De Bary, Comparative anatomy of phanerogams and ferns, 12. fEng. Trans.] 

 "t *' Gefacherte" prosenchyma-cells found by Saupe in species of Sabinea and 

 Sopkora; Solereder, loc, ciL 31 1, 



JTschirch, Angewandte Pflanzenanatomie i : 298. 

 I Weyland, Bull. Herb. Boiss. I ; appendix 3. 1S93. 



