86 HIRUNDO RUSTICA, 



another of the same species*. I construe this, the result of long 

 observation, thus :— Winds blow every year much the same ; birds are 

 hatched ; young seek new dwellings ; mice, insects, berries, &c. are 

 produced suitable for the birds, which are ruled by laws to them invisible, 

 but, with some exception, pretty nearly constant. Little instinct is brought 

 into play ; Nature keeps them in the same groove. 



The bird-road on which Brighton is situated has one branch which 

 arrives about Beachey Head from the opposite coast across the sea, and 

 keeps rigidly to the shore till it reaches Brighton, and passes on, how far I 

 cannot by experience say. This is probably a portion of Herr Palmen's 

 Road A, for birds of the Palsearctic region, which, " leaving the Siberian 

 shores of the Polar sea, near Nova Zembla, and the north of Russia, passes 

 down the west coast of Norway to the North Sea and the British Islands." 



Bird-roads have stations of refreshment, of which Heligoland is one. 



Each Professor mentions a striking fact affecting migration, Mr. Parker 

 one very remarkable point — that 'Hhe amount of pneumaticity of bones by no 

 means follows the development of the power of flight. In the Ostrich, for 

 example, the bones are far more extensively pneumatic than in the Gull." 



Mr. Newton says : — " It has been suspected that where there is any 

 difference in the size of birds of the same species, particularly in the 

 dimensions of their wings, the individuals that perform the most extensive 

 journeys are naturally those with the longest and broadest remiges," — which 

 he supports by examples. 



■^ Note, — A remarkable confirmation of this appeared in ^The Field/ February lOth^ 1876; 

 p. 212: — '^^On Tuesday last Dr. Sclater read a list of additions to the Zoological Society. The 

 most important was the White-spotted Crake [Porzana notata), which was captured at sea off Cape 

 Santa Maria^ Uruguay _, received January 16th. The only other two specimens known are that 

 described in Darwin^s ^ Naturalist^s Voyage ' and the one in the Museum at Paris^ both said to have 

 been taken under similar circumstances/^ 



