ENVIRONMENTAL CONDITIONS 369 
It can then be stored away for use another year. This practice 
is very satisfactory with early-hatched Leghorn chicks. 
Factors Affecting Growth.—There are many factors affecting 
the growth, development, and maturity of chickens. All of these 
logically fall under the one head, Environmental Conditions. 
Environment Constantly Effective-—Environment, which is a 
word used to mean all of the conditions surrounding the individual, 
is a factor which is constantly acting for the good or for bad. As 
the surroundings tend toward bringing about the desired results 
in environmental conditions, rapid growth is attained from the 
very beginning. The growth which a chick makes is determined, 
in part, by the vigor and vitality of the parent stock, and the condi- 
tion of the parent stock, also, in turn, is largely influenced by the 
surroundings to which they were subjected. Again, the vigor of 
Fie. 170.—Growing poultry on free range is the most satisfactory method. Gasoline-heated 
brooders are used on this farm. (Photo by Cornell University.) 
the germ in the fertile egg is influenced by the conditions under 
which the eggs were kept previous to hatching, and the develop- 
ment of the embryo is entirely determined by the surroundings 
to which the egg is subjected during the hatching process, such, for 
example, as variations in temperature, the degree of moisture, the 
amount of turning and cooling, and the general care of the incu- 
bator. At hatching time, differences in size and weight of chicks 
are in direct proportion to the humidity in the incubator, which 
directly affects the evaporation. 
During the brooding period, the factors of environment are 
also of paramount consideration, feed and temperature being the 
controlling ones. It should be the aim of every poultry keeper 
to constantly study his birds, and, by careful selection and elimi- 
nation, keep fewer but better birds. This is especially important 
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