HISTOLOGY 



23 



thickened. A well developed continuous ring of sclerenchyma is 

 present and this is connected with the epidermal layer at short 

 intervals by means of short sclerenchymatous bands. So the 

 parenchymatous cells of the cortex lying outside the sclerenchy- 

 matous ring are divided into small isolated areas. There are three 

 series of vascular bundles. 



FIG. 28.--- -Trail verse section uf a portion of the stem of Eriochloa polvstachya. * 70 

 I. Epidermis: 2. sclerenchyma; 3. vascular bundle. 



One series consists of small bundles lying inside the scleren- 

 chyma ring at the base of each of the connecting bands. The 

 second series is made up of large vascular bundles imbedded 

 in the ring so as to bulge out inside the ring. The vascular 



Fig. 29. — Transverse section of the stem of Setaria glaiu 



x is 



bundles of the third series are found just away from the ring and 

 separated from it by a few layers of parenchymatous cells. (See 

 figs. 27 and 28.) 



