38 PROGRESSIVE POULTRY CULTURE 



climate for fine fowls. Pullets just ready to lay, placed 

 in such environment in the autumn will catch cold, 

 lose condition and very likely become sick with that 

 dread disease the roup. Even if this disgusting dis- 

 ease does not prove fatal it causes decided deterioration 

 in the breeding quality of the birds. 



A change of location from a mild climate to a se- 

 verely cold climate tends to induce disorders of the lin- 

 ing membranes of the mouth, throat and bronchial tubes. 



Changing from a low level to a greatly elevated lo- 

 cation may induce lung trouble. The atmosphere of 

 the high hills is thinner than that of the lowlands. To 

 secure the usual quantity of oxygen for oxydizing the 

 blood, the lungs must take in more air and work faster. 

 This may cause distress or disorder of the lungs for 

 the birds brought to the new location, but they seek to 

 adapt themselves to the condition and in successive 

 generations the size of the lungs and the chest cavity 

 is increased. Changing from high land to low land is 

 likely to cause congestion of the lungs because the air 

 being heavier and having more oxygen than the thin- 

 ner air of the heights, overloads and overworks the 

 breathing apparatus. 



Cold weather calls for increased body-heat which 

 is supplied by extra food. There is increase of appe- 

 tite, more active digestion and assimilation of nourish- 

 ment and a tendency to fatten. 



Nutriment. Climate may thus be united with food 

 In causing effects which if long continued often result 

 in variation. 



Abundance of food tends to encourage breeding, 

 especially if the climatic conditions are comfortable. 



Nutriment of a nitrogenous and phosphatic nature 

 helps to develop early maturity and flesh formation. 



Fatty and starchy foods favor fattening. 



Exercise. The regular exercise of the body-parts 

 has large influence on the form and development of 

 thes'e parts. 



The exercise of a function largely determines its 



