120 
THE VOYAGE OF THE VEGA. 
[chap. 
nest was found only one egg, which, on the 30th July, already 
contained a down-covered young bird. For all the ivory gulls 
which have their home on Spitzbergen there were doubtless 
required several hundred such breeding-places as that at 
Murchison Bay. When to this is added the fact that we never 
in autumn saw on Spitzbergen any full-grown young of this 
kind of gull, I assume that its proper breeding-place must be 
found farther north, on the shores of some still unknown Polar 
land, perhaps continually surrounded by ice. It deserves to 
be mentioned with reference to this, that Murchison Bay was 
covered with ice when Malmgren found the nests referred to 
above. 
Besides these varieties of the gull, two other species have 
been found, though very rarely, in the Polar regions, viz., 
Larus Bahinii, Sabine, and Larus JRmsii, Richards. Although 
I have myself only seen the latter, and that but once (on the 
Chukchi Peninsula), I here give drawings of them both for 
the use of future Polar .explorers. Tliey are perhaps, if they 
be properly observed, not so rare as is commonly supposed. 
Often during summer in the Arctic regions one hears a 
penetrating shriek in the. air. When one inquires into the 
reason of this, it is found to proceed from a kittiwake, more 
rarely from a glaucous gull, eagerly pursued by a bird as large 
as a crow, dark-brown, with white breast and long tail-feathers. 
It is lahhen, the common skua (Lestris parasitica, L.), known by 
the Norwegian walrus-hunters under the name of tjufjo, de¬ 
rived from the bird’s cry, “ I-o i-o” and its shameless thief-nature. 
When the '‘tjufjo” sees a kittiwake or a glaucous gull fly off 
with a shrimp, a fish, or a piece of blubber, it instantly attacks 
it. It flies with great swiftness backwards and forwards 
around its victim, striking it with its bill, until the attacked 
bird either drops what it has caught, which is then immediately 
snapped up by the skua, or else settles down upon the surface 
of the water, where it is protected against attack. The skua 
