342 THE ZOOLOGIST. 



Cypselus apus, but, in flight, seems to have no tail. The birds 

 sometimes chased each other a little, and their call-note was 

 frequently uttered. This is a very short " see," not unlike the 

 short notes sometimes uttered by the British bird when others 

 near are uttering their long " swee-ree." Towards sundown a 

 large number of Chimney Swallows were flying near the Houses 

 of Parliament, which are magnificent piles, in a commanding 

 position. Wilson described the evening assembling or " mobbing" 

 of this species (vide Am. Or. 1812, vol. v.). At sunset the air near 

 one of the buildings became crowded with these birds. They 

 arrived in clusters of from one hundred to four hundred, or 

 thereabouts, flying high, and every minute or two a fresh flock 

 came into view. The general mass extended for some two 

 hundred yards in every direction laterally, and slowly whirled 

 round. All the birds seemed to be chirping, and their combined 

 voices produced a vast rustling sound. 



I repeatedly tried to gauge the numbers of this flock, but 

 always concluded that at least five thousand birds were in the air 

 at the same time. A bystander informed me that all of these 

 would sleep in a certain chimney, which he indicated. I saw none 

 of them alight on any of the buildings, but a dense crowd — a 

 current — of them was perpetually breaking against the gratings 

 towards the summit of a tower-like chimney. The birds, as they 

 approached the openings, were so dense as to occupy more than 

 half of the field of vision there, and since only a small proportion 

 could enter at the same time the majority darted aside from the 

 wall, or, obstructed by others, fell heavily for a few yards, and 

 then, recovering momentum, rose in another current of birds to 

 rejoin the main concourse. But birds entered so fast and so 

 confusedly that I could not count them. Towards dusk the crowd 

 had been greatly diminished. I waited until the last bird had 

 entered the chimney before I left the scene. I was credibly 

 informed that the whole interior surface of the chimney is covered 

 with the nests of the birds. I should have sought an inspection 

 of the premises had not the Parliament then been sitting in an 

 earnest debate. During the brighter hours of daylight not more 

 than a dozen of these birds could be seen ; and four days later, 

 when travelling westward, I saw not more than an average of two 

 per hundred miles, though I was carefully watching for them. 



At Ottawa the Goatsuckers were prevalent, as they were at 





