CLEANLINESS AND TEMPERATURE 283 



Effect of Age on Incubation. — It has been stated that 

 eggs should not be held for any great length of time. How- 

 ever, if it is found necessary to hold the eggs from a week 

 to ten days the eggs should be kept in a dry, cool place, 

 free from excessive air circulation. The best results will be 

 obtained if the temperature of the storage room does not 

 fluctuate beyond the extremes of 50° and 60° Fahrenheit. 



Effect of Cleanliness on Incubation. — No egg should be 

 used for incubation which was excessively soiled in the 

 nest ; in fact best results are obtained where no cleaning 

 has been required. Where eggs are incubated later than 

 the first of April, in middle and northern latitudes they 

 should be disinfected with a weak solution of crude car- 

 boUc acid. Farther south, disinfection should be practiced 

 eariier in the year. The trays and all removable parts of 

 the incubator should be thoroughly scrubbed with a three 

 per cent solution of the above disinfectant, using a stiff 

 vegetable brush, and every portion of the interior thor- 

 oughly sprayed with the same solution. Every possible 

 means should be used to make the incubator aseptic 

 before the eggs are placed in it. The eggs should be 

 put in the machine while it is still surcharged with this 

 antiseptic vapor. Small pans containing a weaker solution 

 of the above disinfectant may be placed under each tray of 

 eggs, so that throughout the entire hatch the eggs are 

 kept in as nearly an aseptic atmosphere as is possible. 



Effect of Temperature on Incubation. — When the tem- 

 perature can be kept uniform, the resulting hatches are 

 more nearly uniform and the chicks stronger than when 

 a fluctuating temperature is maintained throughout the 

 hatch. The proper hatching temperature is 102° to 103° 

 Fahrenheit. 



