i:\IMER GOOSE. 
pose them to have been the brood of that year. Those, od 
the other hand, which I have met with in autmnn, were 
chiefly in that plumage most distant from the appearance 
of the Northern Diver, The size, general aspect, and voice 
of these two birds-^their modes of swimming, diving, and 
flying, are precisely the same. They frequent the same 
situations, and live on the same food. 
I have seen repeatedly, in Zetland, in autumn, and at 
that period when the young of the Glacialis might be ex- 
pected to be full grown, and to arrive in that country (or,- 
if hatched there, to appear in the bays), families, consist- 
ing of two northern divers and two immers, apparently in-i 
separable, and the actions of each toward the other quite 
characteristic of the reciprocal relations of parent and young 
bird. 
The immers, in this contrasted situation, seemed as large 
as the others, but did not swim so erect, or look so lively 
and active, and were chiefly distinguished by the absence 
of the white bars across the neck ; they were also less easi- 
ly alarmed. When fired at, the northern divers took wing 
with facility : the immers also, but apparently more reluc- 
tantly ; and after flying for a short distance, soon alighted, 
when the others, as if unwilling to relinquish the care and 
protection of their ofispring, dropped again beside them. 
That the immer should use its wings less than the adult 
bird, is only what might be anticipated from the analogy of 
the habits of many of the species of this family^ the young of 
which go to sea almost immediately after bursting the shell ; 
and hence, being so early habituated to diving, as a resource 
of food and safety, seldom use their wings, but when driven 
to extremity, or to effect distant and dangerous migration. 
It is accordingly in autumn, immediately after their arrival 
in Zetland, that the immers are most frequently observedf 
VOL. IV, <y ■ 
