THE LATICIFEROUS CELLS OF THE EUPHORBIACER. 449 
nearly to its maximum dimensions in length and breadth, the 
starch-forming corpuscle collects at both ends of the rod-shaped 
grains, and there forms the masses of starch at the end of the 
rod, causing it to assume its remarkable shape resembling a bone. 
The bone-shaped grain formed in this manner consists of a cylin- 
drical rod two to three times longer than broad, having at its ends 
masses of starch of irregular semicircular form,their diameterbeing 
often nearly three times that of the rod. These masses of starch 
deposited at the extremities of the rod are not hemispherical, 
but semicircular disks with a very irregular outline (fig. 4). 
Fig. 4 
d 5 di 
a and b. Mature starch-grains seen from above; c and d, seen from the side. 
The laticiferous cells are polynucleated *, and since, when very 
young, their diameter does not much exceed that of the nuclei, it 
followsthat the starch-forming corpuscles, whichareformed always 
near a nucleus, must be formed on either side of it (figs. 1 & 2). 
The smallness of the diameter of the laticiferous cell necessitates 
the starch-forming corpuscle being much longer than broad, and 
hence it comes that the primitive shape of the grain should be that 
of arod. Later, however, when the laticiferous cell has increased 
in diameter, the starch-rod can also increase its diameter. This 
increase in diameter is not uniform over all the rod, but confined 
principally to its extremities, where the starch-forming corpuscle 
has collected and formed the irregular disk-shaped masses. 
Crüger states that he could find no stratification or polariza- 
tion-cross in these starch-grains. As regards the stratification, 
NügeliT says it is indistinct, and Poulsen f recommends the use 
* Treub, “Sur des cellules végétales à plusieurs noyaux," Archives Néer- 
landaises, 1880. 
t Pflanzenphysiologische Untersuchungen. Heft 2: Die Stárkenkórner, 
page 24. 
1 Botanical Micro-chemistry, by V. A. Poulsen, translated by W, Trelease 
page 85. 
LINN. JOURN.—BOTANY, VOL. XX. 20 
