300 A, F. W, SCHIMPER. 
is in the preceding case. They become gradually less dense 
and resistant, and form only a delicate investment to the 
posterior ends of the starch-grains by the time that they 
have obtained one-half of their definite size. 
In certain cells of the cortex! spindle-shaped bodies contain- 
ing crystalloids are found, which are doubtless starch-forming- 
corpuscles which have produced no starch (fig. 54). In 
the external part of the cortex the corpuscles and the starch- 
grains are small, and always present the same appearance as 
the apical region in its earlier stages. 
An account has now been given of all the. various modes 
of the formation of starch which I have as yet observed. 
They may be conveniently tabulated as follows : 
1. Starch-forming-corpuscles spherical. 
a. They are formed only in the protoplasm which 
invests the nucleus: 
(a) They form starch throughout their whole 
mass ; Colocasia. 
(8) They form starch only in their periphery ; 
Philodendron, Amomum. 
b. They are formed in the protoplasm surrounding 
the nucleus, but to some extent also in other 
parts: 
(a) They form starch throughout their whole 
mass ; Beta trigyna. 
c. They are formed in all parts of the protoplasm : 
(a) They form starch throughout their whole 
mass; Melandryum. 
2, Starch-forming-corpuscles, spindle-shaped. 
a. They are formed only in the protoplasm which 
invests the nucleus : 
(8) They form starch only in their periphery ; 
Phajus. 
c. They are formed in all parts of the protoplasm : 
(a) They form starch throughout their whole 
mass ; Melandryum. 
3. Starch-forming-corpuscles at first spherical, subse- 
quently elongated. 
a. They are formed only in the protoplasm which 
invests the nucleus : 
(8) They form starch only in their periphery ; 
Canna gigantea. 
1 This observation was made on Canna discolor, which in other respects 
resemble the species referred to above. 
