THE GUEAT NORTHERN DIVER. 
275 
position, it is easy to understand wliy they cannot rise from 
the ground, the hind part of the body being elevated, and the 
fore part depressed; yet they rise from the water. This 
appears somewhat unaccountable ; but it is at least a sugges- 
tive fact that in looking through my notes, collected during 
the last twenty years and upwards, I find no mention of a 
Grebe rising from the water without having immediately 
before ascended from beneath, and but one record of a Diver 
being seen to do so; yet both can, as it were, stand in the water 
while they shake their wings. It is easy to perceive how much 
more readily they can rise from the water than from hard 
ground ; but the probability is, that they prefer rising imme- 
diately on coming to the surface, as saving a great amount of 
muscular exertion by utilising the impetus gained in ascending, 
after the manner of certain fish in making their leap. 
THE GEEAT NOETHEEN DIVEE. 
Colymbus glacialis. 
IMMER GOOSE {at all agcs). 
According to Messrs Baikie and Heddle, the Great Northern 
Diver is common in Orkney at all seasons in its immature 
state, old birds being more abundant in winter ; I have not, 
however, heard whether the belief entertained by those gentle- 
men, that it breeds there, has yet been confirmed. With us 
it arrives durmg the month of September in considerable 
numbers, but a large proportion disappear about Christmas. 
In April and May they again become plentiful, but among the 
few which remain throughout the summer adults are rarely 
seen. In the winter months a few at least are constantly to 
be seen in almost every voe or bay, but I have not observed 
more than a dozen at one time, and that was an unusually 
large number. The Immer frequents also the whole Ene of sea- 
board, feeding close along the face of the deep rocks, and when 
the surf becomes too heavy for it there, going boldly seaward. 
