Practical Considerations. 



147 



purposes of ovipositing. The belief that moisture was 

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

 ally prevailed. The power which they exhibit of retaining 

 vitality, and of hatching under water or in saturated 

 ground, is, therefore, very remarkable — the more so when 

 viewed in connection with the results obtained in the suc- 

 ceeding experiments. That the eggs should hatch after 

 several weeks submergence, and that the young insect 

 should even throw off the post-natal pellicle, was, to me, 

 quite a surprise, and argues a most wonderful toughness 

 and tenacity. After they had been dried and soaked for 

 over six weeks, under conditions that approach those of 

 spring, I found a good proportion of the eggs to contain 

 the full-formed and living young, which, though somewhat 

 shrunken, and evidently too weak to have made an exit, 

 were still capable of motion. The water evidently retards 

 hatching. An examination of the submerged eggs that 

 remained unmatched long after others had hatched, which 

 had been under similar treatment up to a certain time, and 

 then transferred to earth, showed all the parts to be unusu- 

 ally soft and flaccid. Yet, when once life has gone, the 

 egg would seem to rot quicker in the water than in the 

 ground. 



The results of Experiments 28 — 25c prove conclusively 

 that water in winter time, when subject to be frozen, is 

 still less injurious to the eggs. 



Altogether, these experiments give us very little encour- 

 agement as to the use of water as a destructive agent; 

 and we can readily understand how eggs may hatch out, 

 as they have been known to do, in marshy soil, or soil too 

 wet for the plow; or even from the bottom of ponds that 

 were overflowed during the winter and spring. While a 

 certain proportion of the eggs may be destroyed by alter- 

 nately soaking and drying the soil at short-repeated inter- 



