538 MARTIN 
of labour rarely excelled in its Class, horizontal galleries in a natural 
or artificial escarpment. When beginning its excavation, it clings 
to the face of the bank, and with its bill loosens the earth, working 
from the centre outwards, assuming all sorts of positions—as often 
as not hanging head downwards. ‘The form of the boring and its 
length depend much on the nature of the soil; but the tunnel may 
extend to 4, 6, or even 9 feet. The gallery seems intended to be 
straight, but inequalities of the ground, and especially the meeting 
-with stones, often cause it to take a sinuous course. At the end is 
formed a convenient chamber lined with a few grass stalks and 
feathers, the latter always beautifully arranged, and upon them the 
eggs are laid. The Sand-Martin has several broods in the year, 
and is much more regular than other Hirundinidx in its departure 
for the south. The kind of soil needed for its nesting-habits makes 
it a somewhat local bird; but no species of the Order Passeres has 
a geographical range that can compare with this. In Europe it is 
found nearly to the North Cape, and thence to the Sea of Okhotsk. 
In winter it visits many parts of India, and South Africa to the 
Transvaal territory. In America its range is even still further, 
extending (due regard being of course had to the season of. the 
year) from Melville Island to Caicara in Brazil, and from New- 
foundland to Alaska. 
The PurpLe Martin of America,! Progne sulis or purpurea, 
requires some remarks as being such a favourite bird in Canada 
and in the United States. Naturally breeding in hollow trees, it 
readily adapts itself to the nest-boxes which are very commonly 
set up for its accommodation ; but its numbers are in some years 
and places subject to diminution in a manner which has not yet 
been satisfactorily explained. The limits of its range in winter are 
not determined, chiefly owing to the differences of opinion as to 
the validity of certain supposed kindred species found in South 
America ; but according to some authorities it reaches the border 
of Patagonia, while in summer it is known to inhabit lands within 
the Arctic Circle. The male is almost wholly of a glossy steel- 
blue, while the female is much duller in colour above, and beneath 
of a brownish-grey. 
Birds that may be called Martins? occur almost all over the world 
except in New Zealand, which is not regularly inhabited by any 
member of the Family. The ordinary Martin of Australia is the 
Hirundo or Hylochelidon nigricans of most ornithologists, and another 
and more beautiful form is the Ariel or Fairy-Martin of the same 
country, Hirundo or Lagenoplastes ariel. This last builds of mud a 
1 In 1840 an example is said to have been killed at Kingstown in Ireland, 
the skin of which is in the Dublin Museum of Science and Art. 
2 The Martin of the French colonists (in the Old World) is an Acridotheres 
(GRACKLE). 
