Garden Work 
stance within the cell consists of carbon, hydrogen, oxygen, 
nitrogen, and sulphur, and is called protoplasm. This 
protoplasm is always active in living cells, but if heated to 
i 20° F. it coagulates, like the white of an egg, and dies. 
If we examine a young living cell through the high 
power of a microscope we can distinguish in its substance 
a little round ball or star-shaped body. This is the nucleus, 
and is composed of carbon (C), hydrogen (H), oxygen (O), 
nitrogen (N), sulphur (S), and phosphorus (P). This 
also contains, in certain instances, even smaller bodies 
when the division of a cell is about to take place. It is 
this nucleus which divides first into perfectly equal parts. 
Then the cell wall forms between the two halves, thus 
making two cells. Sometimes, however, it is a very com- 
plicated process. The nucleus divides, then each of the 
two halves divide again, thus forming four nuclei, after 
which four walls begin to form simultaneously, thus giving 
rise to four new cells at once. 
We thus know what substances are required for the 
building up of the principal parts of a plant, and what is 
the importance of these different parts in the life of a plant. 
But there are many other substances which go to form 
the food of plants, and are found in different parts of the 
plant — such as oil in the Castor-oil plant, inulin in the 
tuberous roots of the Dahlia, while in the Ficus we get 
cystoliths, that is, grape-like clusters of calcium carbonate. 
There are many other substances found in plants, but the 
reader will have to consult special books for a further study 
of these, as they are beyond the scope of a work of this 
kind. It is surprising, however, when we begin our study 
of plant life, to find that these simple substances are taken 
