270 Lieut. R. M. Sperling on the 



(as I am told, for I have never been there at that time of the 

 year), the right time to look for them is after the wind has been 

 blowing from the eastward. 



I think all birds cross the whole breadth of the Mediterranean 

 in one night (unless there happens to be an island in their track, 

 when they will often rest on it for a day) ; and it is perfectly 

 marvellous to me how their instinct guides them so unerringly 

 on their course. Man himself, with all his reason and intelligence, 

 requires a compass and other complicated inventions ; but birds, 

 on the darkest nights, launch fearlessly into the trackless deep, 

 and, guided by nothing but their instincts, accomplish the journey 

 in safety. I do not feel certain that the wind has not something 

 to do with it j for I recollect on one occasion seeing a flock of 

 Turtle Doves utterly confounded by a sudden shift of wind : they 

 settled on the ship, and continued making aimless excursions of 

 about a mile in various directions, but only to return again to 

 make a fresh start. 



As far as my experience goes, it is only the smaller birds that 

 generally cross during the night ; but many of the larger ones, 

 such as the migrating Hawks and Storks and Herons, cross 

 during the day. I don't know what is the reason of this, unless 

 it is that the smaller birds are afraid of being taken at advan- 

 tage by man, birds of prey, &c., should they cross in the day- 

 time. On September 4th, whilst beating into Rhodes with a 

 fresh breeze blowing from Marmorice Bay, I observed a magni- 

 ficent flight of Storks making their southerly migration to the 

 shores of Africa and Egypt : some were flying in triangular-shaped 

 flocks ; but the greater part were in undulatory lines of nearly a 

 mile in length, with their necks folded in, and their legs gathered 

 up under their bodies. Sometimes they would fly at a height of 

 70 yards from the water, while at others they would swoop down 

 so low as nearly to touch it. It is of course impossible to count 

 the numbers in a large flock like this ; I therefore took the 

 mean of the opinions of several people who were looking at it, 

 which made it to be 3250. However, I believe there is a large 

 field left for investigation on this subject, and that the instinct 

 of birds, as connected with their migrations, is one of those 

 things that is anything but well understood at present. Why 



