GOOD PACKING. 335 
undisturbed, it will sit for hours. The site chosen 
for the nest is usually the branch of a young pine ; 
artfully concealed amidst the fronds at the very 
end, it is rocked like a cradle by every passing 
breeze. 
The Black-throated Hummingbird lingers 
around lakes, pools, and swamps where its 
favourite trapping-tree grows. I have occasion- 
ally, though very rarely, seen it hovering over 
flowers; this, I apprehend, is only when the 
storehouse is empty, and the sap too dry to 
capture the insects. They generally build in 
the birch or alder, selecting the fork of a branch 
high up. ’ 
All hummingbirds, as far as I know, lay only 
two eggs; the young are so tightly packed into 
the nest, and fit so exactly, that if once taken 
out it is impossible to replace them. Several 
springs succeeding my first discovery that these 
hummingbirds were regular migrants to boreal 
regions, I watched their arrival. We were 
quartered for the winter close to the western 
slopes of the Rocky Mountains. The winters here 
vary in length, as well as in depth of snow and 
intensity of cold, 33° below zero being no un- 
frequent register. Butit did not matter whether 
we had a late or early spring, the humming- 
