be large or small--that is to say, it enables the one sex to
discover the other with reasonable promptitude.

For the greater part of the year, Guillemots live at sea; singly, in
twos or threes, or in small parties, they move upon the face of the
waters, extending their wanderings far away from land, out into the
broad ocean, where for weeks together they face the gales and heavy seas
of the Atlantic. But in due course and in response to internal organic
changes, they return, like the Warbler, to their breeding grounds--rocky
headlands or islands appropriately situated and affording the
appropriate rock formation. During all these months of wandering, the
majority seem to ignore the land, to pass away from it altogether, and
to spread themselves over the surface of the ocean regardless of
mainland or island. Some useful observations, which throw some light on
the distance that Guillemots are accustomed to wander from land, were
made by Lieut. B. R. Stewart during a number of voyages between various
ports in Great Britain and Ireland and ports in North America,
principally New York and Quebec. Thus, on the 24th March, large numbers
were seen in lat. 55 deg. N., long. 24 deg. W., five hundred miles
approximately from land, though on the following day--four hundred miles
off Tory Island--they were not so plentiful. Again, on the 1st October, in
lat. 53 deg. N., long. 27 deg. W., seven hundred miles or so from land, one
bird was seen, whilst on the following day, in lat. 52 deg. N., long. 21
deg. W., a single individual was washed on board by the heavy seas and
seemed little the worse for the adventure. Within two hundred miles of the
west coast of Ireland, he found them plentiful on various occasions. From
this it is clear that the circumstances under which the bird lives for
many months in succession must impose a considerable strain upon its
constitution; and how it is able to withstand the buffeting of wind and
water, to secure its food, and to endure, is a mystery. It is important,
therefore, that the young bird should be properly nourished and
protected from anything that might harm its constitution, and important,
too, that the parents should be freed from any undue strain during the
course of reproduction.

The conditions which the breeding station has to fulfil are threefold:
in the first place, it must be in proximity to the food-supply;
secondly, it must provide the necessary shelter for the egg and for the
hel