12 



from Bukoba on the Victoria Nyanza, where Emin Pasha met with it on the 12th of 

 January. The late Dr. Fischer also procured a specimen at Kagehi on the 2nd of 

 January. The specimens from the Transvaal are the true C. riparia ; but it is by no 

 means clear that the large flocks noticed by Heuglin on their way south were all 

 C. ripai'ia, though he gives this species as a migrant in N.E. Africa and Arabia, passing 

 south at the end of August and returning in February. He also says that he obtained 

 it in Bogos Land in September. 



In North America the Sand-Martin is as abundant and widely distributed as in the 

 Old World, ranging far north. Sir John Richardson, in the ' Fauna Boreali-Americana,' 

 has the following note: — " The Sand-Martin is remarkable for the extent of its breeding- 

 stations, which embrace the whole continent of N. America. It arrives in Pennsylvania 

 earlier than the other Swallows, or about the third week in March, begins to breed in 

 April, and has commonly two broods in a season. Mr. Hutchins states that it breeds 

 later than any other bird which frequents Severn Biver, sometimes not laying its eggs 

 until near the end of July ; but he observes that it disappears, together with the rest of 

 the Swallow tribe, in the middle of August. Hearne remarks that the Martins, though 

 common in the southern parts of Hudson's Bay, seldom go so far north as Churchill. 

 The whole history of the migratory birds proves that the main object of their wanderings 

 is the obtaining a supply of proper food for themselves and their young. All quarters 

 of the fur-countries abound in the winged insects that Swallows delight to feed upon ; 

 but owing to the large bodies of ice which hang upon the shores of Hudson's Bay until 

 the beginning of August, every breeze from the sea which sweeps the neighbouring 

 country, pi'oduces a depression of temperature sufficient to chill the insects and drive 

 them to shelter; the supply of food to the Swallow tribe, consequently, in that district 

 is so precarious as to render the rearing of their young difficult and uncertain. In the 

 interior of the country, however, the case is different. When the snow is gone, the 

 earth speedily becomes heated; and while the summer lasts, the temperature of the 

 atmosphere continues higher than the hottest w^eather that is ever experienced in the 

 insular climate of Britain, fostering incredible multitudes of mosquitoes. We observed 

 thousands of these Sand-Martins fluttering at the entrance of their burrows near the 

 mouth of the Mackenzie, in the 68tli parallel, on the 4th July, and it is probable, from 

 the state of the weather, that they had arrived at least a fortnight prior to that date. 

 They are equally numerous in every district of the fur-countries wherein banks suitable 

 for burrowing exist, but it is not likely that they ever rear more than one brood 

 anywhere north of Lake Superior." 



The species is said by Audubon to be plentiful on the south shore of Labrador, rarely 

 beo'inniug to breed before June, and laying but once. In the north-west of America 

 it is very much more numerous, and Mr. Nelson gives the following note : — " Along 

 the Arctic sea-coast, as well as the coast of Bering Sea, this is an extremely rare visitant, 

 occurring merely as a straggler during its migration. On the river-courses of the 

 interior, however, it is one of the most abundant, if not the most abundant, species of 

 Swallow. Dall found it nesting in great numbers on the Yukon, and counted over seven 

 hundred Swallows in a saud-bluff near Nuklukhayct ; he found from two to six eggs in 



