5oo 



BOTANICAL GAZETTE 



[DECEMBER 



Scirp 



both 



rasrm 



In the very young stem 

 similar to those of the diaDhraem i 



oem 



(% 



2 and 12). Later 



the cells greatly elongate, some of 



in 



become transformed into tracheids 

 with very indistinct spiral (?) 

 markings, and a secondary con- 

 nection with the xylem of the 

 longitudinal bundle is established 

 (figs. 3 and 4). 



Duval- Jouve (9) mentions the 

 fact that in Sagittaria lancifolia 

 the bundles do not run on the dia- 

 phragms but in them, thus imply- 

 ing that the reverse is usually the 

 case. The diaphragms of Scirpus 

 validus run in the diaphragms, as 

 is shown in fig. 5. 



V. Origin 



Fig. 3.— Scirpus validus: cross- A> 0F THE STELLATE PARENCHYMA 



section of stem: two longitudinal 

 bundles connected 



The canals of many water 

 connection originally with phloem plants are filled with a network of 



(p); tracheids (/) have formed and stellate ceUs> In the case of 



made secondar> 



with 



xylem (*); the connection is not yet &ClTp 



V 



alidus the cells on the 



established with larger bundle; this Upper and lower surfaces of the 

 bundle lies near the edge of a space, diaphragms connect directly with 



these stellate cells, and in some 

 places have been seen to grade into 



but is not connected with a dia- 



food 



them 



It is necessary, therefore, to inquire into tlie origin of the 



stellate tissue. 



Schacht (28) states that 



at certain points. 



arms of the stellate cells are 

 greater amount of nourishment, 

 ^cusses the development of this 



