38 FARM ANIMALS 
a grain of starch is made out of water and carbonic acid 
gas. Some of these starch grains are changed into sugar, 
which, being readily soluble, is transferred by diffusion 
from cell to cell and left in those cells that need it most. 
5. Protein—The formation of the protein constituents 
is more complex than that of starch. In a general way it 
may be said that starch or a starch derivative is united 
in the cells with nitrates and sulphur which have been 
brought into the plant from the soil. The living matter, 
or protoplasm, then breaks up the nitrates in the active 
cells, uniting them in some way with starch, with the re- 
sult that a protein compound is formed. 
6. Fat or oil—Oil 
contains the same 
Z chemical elements as 
See) oie starch. Both starch and 
oil are formed of car- 
bon, hydrogen and oxy- 
gen. In the oil com- 
pounds there is a larger 
number of the carbon 
2 Ibs. A.D oz. 
les, or Hb. of Milk ad * bs 
ieee ‘Beg. of Proted 40n and hydrogen units in 
PROTEIN THE SAME IN pre pention to the on 
Hear shown the weight re uired SCN than in the case of 
ei #9 starch. All plants con- 
ate tain oil or fat in their 
woody tissuey sift! k of it is deposited in the seed 
and fruit. Prote .8 in composition from oil or 
starch in having mtrogen and sulphur in addition to car- 
bon, hydrogen and oxygen. 
7. Ash or mineral materials —When plants or animals 
are burned a portion is left as ash. This consists of the 
mineral materials taken into the plant from the soil. 
When food is eaten by man or beast the minerals are used 
