BIRDS OF THE CAMBRIDGE REGION. 301 



they had "come and gone again" before 1868. This statement may have 

 been intended to apply only to Elmwood ; if used in any much broader sense it 

 was certainly premature or, at least, greatly exaggerated, for Eave Swallows 

 continued to be so common in and about Cambridge for several years after the 

 date just mentioned that one hundred or more might often be seen at one time 

 in early summer, skimming low over Fresh Pond or the neighboring marshes, 

 when the weather was rainy or lowering. Up to about 1S70 fifteen or twenty 

 pairs nested on the walls of an icehouse at Spy Pond and for some ten or fifteen 

 years later a rather larger number frequented the Brown farm at the eastern 

 extremity of Rock Meadow, building their nests under the eaves of a barn and 

 on the timbers which supported the roof of an adjoining open shed. There 

 was a still more populous colony about half a mile from the center of Water- 

 town on the south side of Charles River in Newton. When I visited it on the 

 evening of June 1 1, 1869, there were sixty or seventy occupied nests strung in a 

 long row along the western side of a large barn. The owner of the place de- 

 stroyed them all soon afterwards and the birds did not return. He objected to 

 the presence of the Swallows because their droppings disfigured the barn. With 

 his permission I took a number of their eggs. It was almost dark at the time 

 and all the birds had come in. As a rule I found two of them (a mated pair, no 

 doubt) in each nest, but several of the nests that I examined sheltered tlirce birds 

 each. I regret that I did not kill and dissect the members of one of these trios. 

 There are reasons for suspecting that both Eave and Bank Swallows — as well 

 as Chimney Swifts — sometimes practise either polygamy or polyandry, and I 

 should not have neglected so good an opportunity to obtain evidence bearing on 

 a question of such interest and importance. 



From about 1865 to about 1874 two or three pairs of Cliff Swallows bred 

 every season in the College Grounds, almost within stone's throw of Harvard 

 Square. Their retort-shaped nests were firmly attached to the rough granite 

 walls of Boylston Hall, where they were so perfectly protected from the weather 

 by the overhanging eaves that they remained intact for nearly ten years after 

 the birds had ceased to occupy them. 



During the past decade comparatively few Eave Swallows have been seen 

 in the Cambridge Region, except at their seasons of migration, and the only 

 breeding colony known to exist at the present time is, I believe, that which occu- 

 pies a barn near the Concord Turnpike just beyond Rock Meadow. When I 

 last visited it (in 1898) there were only a few pairs of birds, the descendants, no 

 doubt, of those which used to frequent the Brown farm, at the eastern end of 

 this meadow. 



