360 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 



Experiment 17. — Two egg-masses alternately immersed, drained, and immersed again 

 every two weeks, were placed in moist earth. They commenced hatching two days 

 afterward, and continued to do so for twelve days. Upon subsequent examination, 

 twenty-three out of fifty-two had perished. 



Experiment 18. — Twenty egg-masses immersed from December 28, 1876, to January 

 16, 1877 ; then drained till February 6 ; then immersed till February 27 ; then drained 

 again. On February 3, while dry, they commenced hatching numerously, and a few 

 continued for two days to hatch while immersed. An examination, March 7, showed 

 about half of them still alive, the rest rotten. On March 27 they were drained again, 

 but none subsequently hatched— all having rotted and dried up. 



Experiment \Ha. — Two masses in same conditions as in experiment 18 till February 

 27 were placed in moist earth and all the eggs hatched Mar^h 7-12. 



Experiment 19. — Twenty egg-masses immersed from December 26, 1876, to January 

 23,1877; then drained till February 20; then submerged again. They commenced 

 hatching on the 6th of February, and continued two days after the second submerg- 

 ence. On the 7th of March but about 5 per cent, had rotted. On March 20 they were 

 drained again, but none subsequently hatched, except five eggs from two pods at once 

 placed in earth. 



Experiment 20. — Two egg-masses immersed for four weeks ; then drained for two 

 weeks ; then immersed for one week ; then placed in moist earth. They commenced 

 hatching seven days afterward, and continued to do so for six days. Subsequently 

 examined, one of the masses was rotten ; the eggs in the other had all hatched. 



Experiment 21. — Twenty egg-masses kept from December 26, 1876, in earth saturated 

 with moisture. On February 23, 1877, they commenced hatching, and continued to do 

 so till March 7, when all were found ta have hatched, except one pod, which was rot- 

 ten. 



Experiment 22. — Twenty egg-masses, alternately placed every five days, from Decem- 

 ber 26, 1876, in earth saturated with moisture and in earth which was very dry. Com- 

 menced hatching February 14, and continued till March 7, when, upon examination, 

 all had hatched, except nine of the pods, which were rotten. 



Experiment 23. — Twenty egg-masses im'mersed and exposed outdoors December 26, 

 1876. From that time till April 9 the water was frozen and completely thawed at nine 

 different times, the vessel containing them, which was of glass and admitted the sun- 

 light, several times breaking. The changes were as follows: Frozen till January 10; 

 then thawed till the 12th ; then frozen till the 18th ; then thawed till the 20th ; then 

 frozen till the 26th; then thawed till February 20; then partly fiozen till the22d; 

 then thawed till the 26th; then frozen till the 27th; then thawed till March 5; then 

 frozen till March 10 ; then thawed till March 15 ; then frozen till the 16th ; then 

 thawed till the 24th ; then frozen till the 25th. Examined on the 7th of March, only 

 one pod was found rotten ; the others apparently sound. On the 9th of April all with 

 the exception of twelve eggs were found rotten, the masses having become disin- 

 tegrated and the eggs for the most part lying singly at the bottom. 



Experiment 24. — Two egg-masses under same conditions as in experiment 23 till Feb- 

 ruary 9, when they were brought in-doors and placed in earth. One was dried up on 

 the 16th ; the other commenced hatching on the 27th., and when examined on March 

 7 all the eggs in it were found to have hatched. 



Experiment 25. — Two egg-masses under same conditions as in experiment 23 till Feb- 

 ruary 27, when they were placed in earth in-doors. Exami&ed March 7 they were 

 found sound, and near the hatching point. On March 20 they commenced hatching. 



Experiment 2oa. — Two egg-masses under same conditions as in experiment 23, up to 

 March 6, were then placed in earth in-doors. They commenced hatching March 23, 

 and continued till April 3. Subsequently examined, but eight out of the* fifty-four 

 eggs were shrunken and dead. 



Experiment 25&. — Two egg-masses under same conditions as In experiment 23, up to 

 March 27, were then placed in earth, as above. April 14-20 ten hatched. Subse- 

 qaently examined, the rest were found rotten. 



Experiment 25c. — The twelve eggs remaining April 9 from experiment 23 were placed 

 in earth. Five out of the twelve hatched April 20-26. The rest were subsequently 

 found rotten. 



These experiments establish a few facts that were somewhat unex- 

 pected. The insect is a denizen of the high and arid regions of the 

 Northwest, and has often been observed to prefer dry and sunny places, 

 and to avoid wet land, for purposes of ovipositing. The belief that 

 moisture was prejudicial to the eggs has, for these reasons, very gener- 

 ally prevailed. The power which the^ exhibit of retaining vitality, and 

 of hatching uader water or in saturated ground, is, therefore, very re- 



