Practical Considerations. 



141 



( 



, of which are herewith summed up. By reference to the 

 meteorological table given on p. 152, the exact temperature 

 , at any of the dates mentioned, up to March 10, can be 

 j ascertained. 



1 Experiments to test the Effects of alternately 

 < Freezing and Thawing. — The eggs in the following 

 1 series of experiments were obtained early in November, 

 at Manhattan, Kansas, under similar conditions. They 

 were mostly in a fluid state at the time, and none but 

 good and perfect masses were used. They were all 

 carefully placed in the normal position at the surface 

 of the ground, in boxes that could be easily removed 

 from place to place. The experiments commenced No- 

 vember 10th, 1876, and ended in April, 1877. Dur- 

 ing November and December the weather was severe, 

 while during January and February it was largely mild 

 and genial for the season. In March again there was much 

 frost. 



The temperature in my office, into which all the eggs 

 when not exposed were brought, ranged during the day 

 from 65° to 70° F., rarely reaching to 75°. During the 

 night it never dropped below 40°, and averaged about 55°. 



Experiment 1. — Fifty egg-masses were exposed to frost from 

 November 10th to January 10th, and then taken in-doors. In twenty 

 days they commenced hatching, and continued to do so for thirty- 

 eight days thereafter. 



Experiment 2. — Fifty egg-masses exposed at the same time to 

 frost. Brought in-doors on December 10th. On December 31st they 

 commenced hatching numerously and continued to hatch till the 

 10th of January, 1877, when the remainder were exposed again. 

 The weather being subsequently mild, some hatched on each warm 

 day until the 26th. None hatched thereafter, and upon examina- 

 tion, subsequently, all were found to have hatched. 



Experiment 3. — Fifty egg-masses exposed at same time. Brought 

 in-doors December 1st. Kept there till the 22d without any of them 



