298 A, F. W. SCHIMPER, 
thin protoplasmic lining of the youngest cells is very dense 
and glistening ; its surface is at first smooth, but it becomes 
uneven. The prominences become rounded off and form 
spheres or spindles, whilst the substance between them 
becomes ordinary protoplasm. 
The formation of starch-grains begins very early, even 
before the complete differentiation of the starch-forming- 
corpuscles. It is indicated, as in Beta, by a turbidity in 
the corpuscle,and by its turning blue when treated with 
iodine. The grains become gradually larger and more 
numerous, and polyhedral in consequence of mutual pres- 
sure. The substance of the corpuscle diminishes and dis- 
appears. 
' The young white tubers, surrounded by leaves, and the 
roots of Phajus grandifolius, contain rather large starch- 
grains of a triangular, much flattened form, and of definite 
excentric structure (figs. 33—41). 
The young starch-grains are attached by their posterior 
ends to rod-shaped bodies which lie parallel to the broadest 
sides of the starch-grains. These rods give the same re- 
actions as the starch-forming-corpuscles, and the study of 
their development shows that they are bodies of this kind. 
When treated with water they become spherical vesicles and 
then disappear. 
Bodies of this kind, which are not attached to starch- 
grains in older cells, are found in the epidermis, both of old 
tubers which have become green and in young ones, col- 
lected around the remarkably granular nucleus.’ In very 
young cells they produce small starch-grains. I was able 
to study the development of these peculiar starch-forming- 
corpuscles, but the small amount of the material prevented 
me from making out all the details with certainty. In the 
youngest cells the nucleus is surrounded with a layer of 
dense glistening protoplasm, as in the epidermis of Philo- 
dendron. At a later stage numerous minute delicate spin- 
dles are found lying in the protoplasm which now presents 
its ordinary appearance. These spindles soon give rise 
to small starch-grains which disappear. The corpuscles 
enlarge and assume, even when the starch is being formed, a 
rod-shape. 
Exactly the same apparently takes place in the root (figs. 
33—36), where it is easy to observe the starch-forming-cor- 
puscles before the appearance of the starch-grains and to 
follow the development of the latter. The corpuscles which 
are collected round the nucleus, and which are at first 
1 Gris, ‘Ann. d. Sci. Nat.,’ sér. 4, t, vii, pl. 8, fig. 4. 
