232 VEGETABLE PHYSIOLOGY 
than mere specks, make their appearance, while the highest 
powers of the microscope fail to enable an observer to 
detect the presence of any form of plastid before or during 
the deposition. Instead, the minute granules can be seen 
to arise in a homogeneous transparent hyaline protoplasm. 
The same phenomenon occurs in connection with the 
deposition of starch grains in the cells of young developing 
embryos, in the early stages of the formation of the seed. 
The protoplasm of the cells may be seen to have the form 
of a coarse network with many small meshes, which are 
empty spaces or contain only cell-sap. There is no leuco- 
plast inside them, nor anything comparable to one. The 
starch grains originate in these meshes at some point in 
contact with the protoplasm and gradually increase in size 
till they fill them. In some cases simple, in others com- 
pound, grains of starch are thus developed. 
In a large number of the Fungi which store up carbo- 
hydrate reserve materials, these take the form of glycogen. 
This is a substance which presents a somewhat close 
resemblance to starch, being readily converted into sugar 
in a manner almost, if not quite, identical with that 
which is characteristic of starch. It is coloured brown by 
iodine. Jt is usually deposited in amorphous form in the 
interior of the fungal hyphe, or of particular cells of them. 
In a few cases there are definite granules, which to a 
certain extent resemble grains of starch, and which have 
been stated to originate in certain corpuscular bodies 
resembling leucoplasts. In most cases the deposition 
appears to be effected by the protoplasm. 
Another carbohydrate which shows a certain resem- 
blance to starch, though perhaps not a very close one, is 
inulin. The distribution of this material is much more 
limited than that of starch, but it is known to occur in 
several groups of plants, being conspicuous in many of the 
Composite among the Dicotyledons, and in several species 
of the Liliaceae, Amaryllidacee, and other allied orders 
among the Monocotyledons, Like starch and glycogen, it 
