THE TISSUES OF PLANTS. 31 
from that of the majority of mosses. In Horsetails, for 
example, it is an inverted triangular pyramid, having a 
convex base. The segments (daughter-cells) are cut off by 
alternating partitions parallel to the plane sides of the 
pyramid, as in the mosses. In some mosses and ferns, how- 
ever, the apical cell is wedge-shaped—i.e., with only two 
surfaces—and in such cases two instead of three rows of 
meristem-cells are formed. 
56. In the flowering plants the primary meristem is de- 
veloped from a group of cells, instead of from a single one; 
they therefore have no apical cell. This group of cells 
occupies approximately the same position in the organs of 
flowering plants as the apical cell does in the mosses and 
ferns; it is composed of cells which have the power of 
indefinite division and subdivision. 
57. The apical cell and its actively growing daughter- 
cells in its immediate vicinity, or, in the case of the flower- 
ing plants, the apical group of cells with their daughter- 
cells, constitute the Growing Point or Vegetative Point 
(punctum vegetationis) of the organ. When this active 
portion is conical in shape it is also called the Vegetative 
Cone. 
Practical Studies.—(a) Make very thin longitudinal sections of a 
root of Indian corn, The large strong roots which first start out 
from the germinating grain, and the youngest states of those which 
appear just above the ground, upon the large plants, are best for 
these specimens, Stain some of the sections with carmine, 
(0) Make very thin longitudinal sectious of the opening buds of the 
lilac or elder. 
(©) Make similar sections of the tips of the young shoots of aspara- 
gus. Stain with carmine. 
(d) Make cross and longitudinal sections of the youngest states 
of the stems of the pumpkin, squash, and asparagus, and compare 
with similar sections of older parts, 
