144 The Rocky Mountain Locust. 



changes ; the warm atmosphere of the room having great 

 drying power. 



Experiment 10. — Ten egg-masses kept under water in-doors f roni 

 December 5th to December 26th, 1876, the water becoming quite 

 foul. They were then removed to earth and kept in a hatching 

 temperature. They commenced hatching January 11th, 1877, and 

 continued to do so till February 5th — all having hatched. 



Experiment 11. — Twenty egg-masses kept underwater in-doors 

 from December 26th, 1876, till January 2d, 1877 ; then left dry till 

 the 9th ; then submerged again till the 16th, when they were drained 

 again. On the 20th, eighteen young hatched, and others continued 

 hatching till the 23d, when they were submerged again. From the 

 26th to 30th, a few hatched under water, successfully getting rid of 

 the post-natal pellicle, and living for some hours afterward in the 

 water. On the 30th they were drained again, and continued to 

 hatch. On February 6th, they were again immersed, and continued 

 to hatch on the 7th. On the 15th, 22d, 29th, and March 7th, they 

 were alternately drained and immersed ; but none hatched after 

 February 7th, and the remainder proved upon examination to have 

 been destroyed, most of them being quite rotten. 



Experiment 12. — Two egg-masses taken from the lot in Experi- 

 ment 11, on February 7th, and placed in moist earth. Every egg 

 subsequently hatched. 



Experiment 13. — Two egg-masses taken from the lot in Experi- 

 ment 11, on February 22d, and placed in moist earth. All hatched. 



Experiment 14. — Twenty egg-masses alternately immersed and 

 drained every two weeks from December 26th till March 6th. None 

 hatched, but three-fourths of the eggs were at this date sound, 

 the embryon full-formed and active as soon as released, but pale, 

 and evidently too feeble to burst the egg-shell. The rest were 

 killed and more or less decomposed. 



Experiment 15. — Two egg-masses, after immersion for two weeks, 

 were placed in moist earth. They began hatching twenty-two days 

 afterward, and continued to do so for six days. It was subsequently 

 found that only seven out of forty-eight eggs had collapsed and 

 failed to hatch. 



Experiment 16. — Two egg-masses immersed for two weeks and 

 drained for two weeks ; then placed in moist earth. Six days after- 

 ward they commenced hatching, and continued to do so for two 



