168 Mr. W. Eagle Clarke on the 



places, for both eggs and dead young birds of previous 

 seasons were numerous in the tenanted holes containing the 

 fresh eggs. This fact indicates that a very serious waste of 

 life takes place in some seasons, if not annually. It may 

 be accounted for by the late arrival of the bird at its 

 breeding-stations, which, coupled with the lengthened 

 period of incubation characteristic of all Petrels, results in 

 winter setting in ere the eggs are hatched, or the young, 

 which develop slowly, are old enough to leave the nesting- 

 holes. Another, and perhaps more probable, explanation is 

 that the disasters notieed were due to a succession of cold 

 summers, which are actually known to have occurred. None 

 of the eggs in the summer of 1903-01- had been hatched when 

 the Expedition left the islands on February 21st. These 

 facts would seem to indicate that the South Orkneys lie at 

 the extreme limits of possible breeding for Wilson's Petrel. 

 Indeed for many individuals of this species, perhaps all, 

 during some seasons the climatic conditions place the islands 

 distinctly beyond that range; though it breeds further south, 

 most likely with similarly disastrous results. 



From 7 to 11 p.m. these birds flitted about the cliffs and 

 over the head of Scotia Bay in great abundance, and in 

 striking contrast to their habit in the day-time, when only 

 occasionally was one to be seen on the water, though there 

 were probably many at sea oft' the islands. 



The nest figured (Plate X. fig. 2) was situated at the 

 bottom of a crack in the rock, about four inches wide and 

 two feet deep. It was the only one found which w r as open 

 enough to permit of a photograph being taken, and then 

 only under particular circumstances as to time. At about 

 7 a.m. the sun shone for a few minutes directly into the 

 crack, and it was during those moments that this unique 

 picture was secured. 



Eight eggs average 33*7 x 24 mm. The largest is 36 x 

 24 mm., and the smallest is 32 x 23 mm. 



Fregetta melanogaster (Gould). 



Cymodroma melanogaster Cat. B. xxv. p. 361. 



On December 5th Dr. Pirie discovered a pair of unknown 



