BIRDS OF THE UNITED STATES. 
95 
inches or more, so that the water may readily pass beneath them. Here 
the eggs are scattered at distances of three or four inches from each other, 
and are incubated, as in the case of the Ducks, by the birds sitting flat 
upon them. Whereas, upon an exposed rock, each bird stands almost 
upright on its egg. 
There yet remains a very strange fact concerning this Auk, which 
needs to be noted. It pertains to the number of eggs which is to consti- 
tute a nest-full. When nesting occurs in secluded situations, where 
security against tidal currents, and divers accidents, is to be gained, 
in the majority of instances, two eggs are found under a single female. 
In exjwsed situations, on the other hand, it is a rare occurrence to find 
more than one egg as a complement. 
The above statements, which are substantially those of Audubon, have 
been repeatedly verified by other observers, some of whom are among the 
writer’s most reliable correspondents. At first we were disposed to question 
their accuracy. We could not see what advantages a sequestered situation 
had over one that was open and exposed, so as to lead the birds to double 
their number in the former ease. Our only way out of the difiiculty 
then, was by supposing the two eggs to be laid by different birds, in close 
proximity to each other. For want of the necessary room to accommodate 
the ’two females, it became the duty of one or the other to assume the 
responsibility of them. Owing to the great difficulty of distinguishing 
the eggs of this species from those of the Murre or Foolish Guillemot, 
which most odlogists have experienced, and which Audubon does not seem 
to have encountered, it occurred to us that as the Auks are prone to 
drop their eggs alongside of those of the Guillemots, maybe the two 
eggs were those of distinct species, and not the product of the one under 
consideration. 
Without further mincing of matters, there does not seem to be any 
valid reason for doubting the authenticity of Audubon’s statements. But 
as a true student of Nature, it is our duty to receive the facts, confirmed 
