416 CONSERVATIVE ORGANS. [LECT. VIII. 



cuticle at /. /. /. /. (Fig. 4, A.), so as to give the 

 stem its striated aspect ; and the third band (c. c.) 

 is composed of entire vessels. Although we may 

 regard the part just described as analogous in 

 some respects to the cortex in ligneous stems, yet 

 in others it differs materially from that organ; and 

 it can neither be separated entire from the parts 

 beneath, nor can the bands be detached from 

 each other without destroying the organization. 

 Immediately within the vascular band of the 

 cortex we find the cellular mass d. d. d. d. com- 

 posed of cells which appear more or less regular 

 hexagons in the transverse section (Fig. 4, A) ; 

 but in the longitudinal (B) their length is seen to 

 be more than twice the sum of their diameter. 

 They are larger and more regular in the centre of 

 the stem ; and the hexagonal shape is sometimes 

 lost, in order to accommodate them to the forms 

 of the vascular fasciculi. The cells are filled with 

 a thin mucilaginous fluid, which is more viscid in 

 the vicinity of the vascular band of the cortex 

 and the vascular fasciculi; but, as the season ad- 

 vances, it almost disappears in the central cells, 

 which then assume the character of the pith in 

 dicotyledons. All the cells are perforated. The 

 vascular fasciculi contain from seven to ten cen- 

 tral vessels ; one of which (//) is very large, 

 and the others (g. g. h. h.) smaller in a regu- 

 lar ratio as they are distant from it, or towards 



