182 ABOUT FUNGI. [CHAP, 
fungi, for we have seen (Chapter II. avte) that plants 
possessing chlorophyll give off oxygen. 
Fungi are essentially either parasites or scaven- 
gers,—or both. We have seen (Chapter II.) that 
sreen plants have the power of constructing protein 
out of a few elementary substances. Not so fungi; 
their food must be organised,—that is, the elementary 
substances must be chemically combined to form a 
part of some previously existing animal or plant. 
Thus sugar is a vegetable product which consists of 
the chemical elements Carbon, Hydrogen, and Oxy- 
gen. Torula can grow and flourish in a solution of 
sugar and water, though it cannot live in a mixture 
of Carbon, Hydrogen, and Oxygen, unless they have 
been elaborated into a compound by being taken into 
the vegetable economy. 
The reproduction of Torula is effected in the 
simplest manner possible. It either develops trans- 
verse partitions across the cell and thus divides itself 
into two or more cells ; or, what is more common, it 
produces a swelling or bud at some point outside the 
cell-wall, and this bud grows into a full-sized cell 
identical in every respect with that from which it 
originated. Fig. 134, B, shows how this process of 
budding goes on. 
All fungi are composed of cells similar in every 
respect to Torula, though in the higher species these 
cells are combined in a variety of ways to produce 
forms varying greatly from each other. As an ad- 
vance in organisation upon Torula we have Peuz- 
cillium (fig. 135). Here we have simply a number of 
cells like Torula, a little drawn out and placed end 
