THE DIFFERENTIATION OF THE PLANT-BODY 33 



sclerenchyma round the periphery, and strands occur also 

 in connection with the bundles. Sometimes these are con- 

 nected by bands of sclerenchyma lying between them. In 

 Fimbristylis (fig. 32, 7) there is a ring of sclerenchyma in 

 the cortex and patches around the periphery, which in other 

 cases are joined like those of the former type. In the stems 



lG. 32. DIAGRAM SHOWING THE CHIEF DISPOSITIONS OB 1 THE SKELETAL 

 APPARATUS IN A STEM WITH FIVE COLLATERAL BUNDLES (IN TRANSVERSE 

 SECTION). 



(The sclerenchyma is black ; the bast of the bundles is white ; 

 the wood is dotted.) 



1, Type without accessory sclerenchyma ; 2, Equiselum ; 3, Bambusa ; 

 4, Pennisetum ; 5, Scirpus ; 6, Erianthus ; 7, Fimbristylis ; 9, Typha ; 

 10, Juncus ; 14, Cladium. (After Van Tieghem.) 



of Typha (fig. 32, 9) a band of sclerenchyma lies at the 

 back of each bundle, and either a ring or some isolated 

 strands may be found in the cortex. The stem of 

 Jumus (fig. 32, 10) shows these two forms combined 

 together. 



Still more complicated cases show sclerenchyma arising 

 in all three regions, sometimes the bands being all inde- 

 pendent, sometimes united in various ways. In Cladium 

 Mariscus (fig. 32, 14) those of all the regions are united 



3 



