The Audubon Societies 



317 



four) and found about half of them to 

 contain the dried bones of embryonic 

 birds, which I calculated must have been 

 killed six weeks before. The rest of the 



times, and their state of preservation 

 showed this to be six weeks and one week 

 previous to July 30. I then recalled that 

 the Naval Station at Diamond Island, 



NEST AND EGGS OF COMMOX TERN OX HADDOCK ROCK 



eggs contained embryos, which were still 

 in an only slightly decomposed condition, 

 and appeared as though they had been 

 dead about a week. Many of the eggs were 

 just ready to hatch at the time they were 

 killed — in fact, some of them were pipped. 

 The set of four which I did not open 

 appeared so bright, and the nest was in 



twelve miles nearer Portland, had engaged 

 in target-practice on July 23, and I later 

 learned that target-practice was held at 

 this station during the first week in June. 

 The correspondence of these dates with 

 the time the eggs were killed on Haddock 

 Rock is itself significant; and, when I 

 recall the fact that the atmospheric shock 



YOUNG COMMON TERN HIDING ON HADDOCK ROCK, JULY 30, 1913 



so good repair, that I was encouraged to 

 believe that they had been recently laid. 

 The point I wish to emphasize is that 

 all the eggs showed conclusive evidence 

 that they were killed at only two different 



from this cannonading jarred the windows 

 of the houses on Baily Island, near 

 Haddock Rock, I am satisfied that it was 

 this aerial vibration from the cannonading 

 on Diamond Island that killed the eggs on 



