210 The Botanical Gazette. [July, 
tercellular spaces are large and plentiful by reason of the pe- 
culiar manner of junction of conical ended cells. In many 
cases, however, the entire ends of adjacent cells are pressed 
arrangement are well fitted to undergo-great variations in size, 
while the large intercellular spaces, affording plentiful space 
for the reception of expelled cell sap, make possible rapid 
changes in the-tension of this tissue. The parenchyma is 
protoplasm t- 
_ The basal portion differs from this in its regular sds! ie 
Ene, symmetrical arrangement of the xylem, heavier st ous 
ing of the collenchyma, and early formation of a weer 
distinct cambium zone. Lignification has extended slig 
** PENHALLOW: Proc. Roy. Soc. Canada, vol. 4, sec. 4, 1886, p. 54 
