148 



migrations, however, the hosts of hirundo moving to or from their 

 northern breeding places greatly outnumber forsteri. 



The above is true of Illinois, and will, I think, apply equally well to 

 other points in the Mississippi valley, where the two forms occur. 

 This and the preceding are in breeding plumage when they arrive In 

 spring. White feathers commence to replace the black cap early in 

 August in forsteri. Although I have been aware that S. forsteri nested 

 in this vicinity for several years, it was not until the middle of June, 

 1876, that I had the pleasure of examining one of their nests. While 

 we were collecting eggs among the wild rice patches, on Grass Lake, 

 June 14th, Mr. Douglas observed a pair of these terns hovering near a 

 small patch of Saggitaria leaves growing in several feet of water, and 

 rowing to the spot found the nest, which was a loosely built structure 

 of coarse pieces of reeds resting upon a mass of floating plants and 

 concealed from view by the surrounding leaves. Upon the side of the 

 nest was a single young bird, about to scramble into the water, but 

 upon seeing Mr. Douglas it crouched to avoid being observed, and 

 was captured. A thorough search at the time failed to reveal any 

 other young ones, so the adults, which had been darting and scream- 

 ing about his head, were secured, with" a second pair which had es- 

 poused the cause of their companions. Their anxiety we afterwards 

 found to be the proximity of an unfinished nest, similarly situated. 

 That evening we found and secured two more young upon the nest 

 found in the morning. The next morning fortune favored me, and, 

 while passing between several floating masses of decaying vegetable 

 matter I observed four small heaps of wild rice stalks resting upon 

 one of these masses, and on a nearer view, to my delight they proved 

 to be the desired nests containing eggs. The nests were situated in- 

 a line, and the two outer ones were not over twenty-five feet apart. 

 The only materials used were pieces of wild rice stems, which were 

 obviously brought from some distance, as the nearest patch of rice 

 was several rods distant. The nests were quite bulky, the bases being 

 two feet or more in diameter. The greatest, depth was about eight 

 inches, and the depression in the centre so deep that while sitting in 

 the boat a rod away the eggs were not visible. Two of the nests con- 

 tained three eggs, and two contained two eggs, each. The following 

 are the measurements of three of the eggs, representing the amount 

 of variation: 1-70 by 1-25; .1-75 by 1-20 and 1-68 by 1-25. The ground 

 color varies from a pale greenish to a warm brownish drab. The spots 

 and shell markings are of a varying shade of brown, distributed much 

 as in the other small tern's eggs. 



While near the nests the birds, were circling high overhead, now 

 and then uttering a harsh cry, but, concealing myself in the rice near 

 by, I soon secured several of the parent birds as they flew about the 



