46 



MR. C. BAILEY ON THE STRUCTURE ETC. 



Fi^. 66. 



In his ' Beitrage/ pp. 51 & 52, Magnus describes Naias 

 graminea as possessing bast -cells in certain fixed positions 

 in the leaf^ namely^ close to the margin^ and immediately- 

 above and below the central bundle on the upper and lower 

 surfaces of the leaf (see figs. 31-33 on Plate VII.) . These 

 bast-cells I cannot discover, after prolonged search, in 

 any portion of the Eeddish plants ; but as Magnus states 

 (p. 52) that Damietta specimens collected by Ehrenberg, 

 and Cairo specimens collected by Schweinfurthj also have 

 these bast-cells wanting, it is clear that the Reddish plant 

 corresponds in this particular with the plants from Lower 

 Egypt. 



On the other hand, the plant from the Italian stations 

 possesses bast-cells. I found them clearly 

 marked in specimens in my herbarium col- 

 lected by Signor Malinverni, '' in stagnis fossis 

 et oryzetis circa Quintum Vercellensis ditionis 

 pagum sestate 1875 ;''^ the accompanying figure 

 has been drawn from the leaf of one of these 

 plants (fig. 66). 



The line of libriform cells is the central one 

 of the three series which I have drawn j it is 

 most clearly apparent, when viewed as a trans- 

 parent object, from the circumstance that its 

 cells do not contain chlorophyll, and hence it 

 is visible as a transparent colourless line in the 

 midst of green tissue. 



An isolated bast-cell is given in fig. 34 on 

 Plate VIL, and their position in the leaf is 

 shown in figs. 31-33 on the same Plate at 

 the points marked b. In the upper part of fig. 32 the 

 single cell seems to have been multiplied into three, but, as 

 Dr. Magnus explains in his memoir, these long Y-shaped 

 cells are arranged in a single linear series at the edge 



