EFFECTS OF IRRIGATION ON THE EGGS. 359 



Spring breaking of our lands remained perfectly good till upturned by second plow- 

 iEg one month to six weeks later. — [ Jas. Moore, Bastrop, Tex., May 8, 1877. 



Deep plowing retarded Latcbing. After all others were hatched the deeply plowed 

 land was stirred, which brought on a new crop. — [G. B. Brown, Guilford, Kans. 



Plowed in October, 1876 ; sowed to rye in November, on bottom land, but gravelly; 

 cut the rye second week in July (prematurely) because of drought. As soon as th© 

 rye was cut the locust-eggs hatched in large quantities. — [Experience of M. K. Lever- 

 son, of Leversou's ranch, Colorado. From all we could learn the eggs were not turned 

 under deeply. 



3. Irrigation.— This is feasible in much of the country subject to 

 locust ravages, especially in the mountain regions, where, except in ex- 

 ceptionally favorable locations, agriculture can be successfully carried 

 on only by its aid, and where means are already extensively provided 

 for the artificial irrigation of large areas. Where the ground is light and 

 porous, prolonged and excessive moisture will cause most of the eggs to 

 perish, and irrigation in autumn or in spring may prove beneficial. Yet 

 the following experiments prove that it is by no means as effectual as 

 is generall;^ believed, and as most writers have assumed to be the case. 



Experiments to test the wfluence of moisture itpon the eggs. — The follow- 

 ing series of experiments was made with eggs also brought from Man- 

 hattan, Kans. They were dug up in December, and were sound, and 

 much in the same condition as those in the preceding series. 



The water in all but the last three, or Experiments 23, 24, and 25, 

 was kept in the office at the temperature already stated, and changed 

 only when there was the least tendency to become foul. In the alternate 

 submergence and draining, the eggs were submitted to the most severe 

 hygrometric changes, the warm atmosphere of the room having great 

 drying power. 



Experiment 10. — Ten egg-masses kept under water indoors from December 5 to De- 

 cember 26, 1876, the water becoming quite foul. They were then removed to earth atd. 

 kept lU a hatching temperature. They commenced hatching January 11, 1877, and 

 continued to do so till February 5— all taving hatched. 



Experiment 11. — Twenty egg-masses kept under water in-doors from December 26, 

 1876, till January 2, 1877 ; then left dry till the 9th; then submerged again till the 

 16th, when they were drained again. On tte 20th eighteen young hatched, and others 

 continued hatching till the 23d, when they were submerged pgain. From the 26th to 

 30th a few hatched under water, successfully getting rid ot 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 6 they were again immersed, and con- 

 tinued tc^hatch on the 7th. On the 15th, 22d, 29th, and March 7 they were alternately 

 drained acd immersed ; but none hatched after February 7, 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 experiment 11, on February 

 7, and placed in moist earth. Every egg subsequently hatched. 



Experiment 13. — Two egg-masses taken from the lot in experiment 11, on February 

 22, and placed in moist earth. All hatched. 



Experiment 14. — Twenty egg-masses alternately immersed and drained every two 

 weeks from December 26 till March 6. 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 Ijurst 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 afterward they commenced hatching, and con- 

 tinued to do so for two days. Subsequently examined, twentj -eight out of fifty-four 

 eggs had perished. 



