1024 REPORT OF STATE GEOLOGIST. 



until the set is complete. It is said generally to rear two broods a 

 season. The period of incubation is given at ten days to two weeks. 

 The male supplies the female with food, but after the young are 

 hatched it requires the combined efforts of both parents to keep them 

 supplied with food, generally insects. Mr. Loucks mentions one nest 

 that contained ten eggs, and thinks more than one bird must have 

 laid them. In the southern part of the State they sometimes have 

 full sets of eggs in April, but in its more northern homes it seldom 

 has a complement before late in May. Mr. Eobert Eidgway found a 

 nest and four fresh eggs near Mt. Carmel, 111., April 27, 1878. May 

 13, 1891, Mr. H. W. McBride found no completed nests in Lagrange 

 County, Ind. May 28, 1896, Mr. J. G. Parker, Jr., found two nests 

 containing young, and one with fresh eggs, along the Kankakee River, 

 near Kouts. May 31, 1885, Mr. Coale found nests containing fresh 

 eggs at Davis Station. At the same place, June 8, 1884, he found 

 four nests with eggs partly incubated, and a week later, June 15, he 

 found young out of the nests. 



The localities they select for summer homes are of their own choos- 

 ing, and we do not understand the rule they apply or the reason for 

 their choice. Often in one locality they are common, while another, 

 near by it, may be passed over and no Prothonotaries frequent it. 

 They are not usually known. The uninviting places they seek are not 

 commonly frequented by men other than naturalists, and the birds do 

 not wander from the precincts of their retreats. They may, therefore, 

 be very abundant in a swamp and be absolutely unknown to the in- 

 habitants of the neighboring farms. When the young can fly and 

 care for themselves, perhaps in July, they begin to become less notice- 

 able. Fewer and fewer their numbers grow, until finally the last have 

 passed away, retracing their steps of the preceding spring. The latest 

 record I have is September 3, 1884, when a bird of the year was taken 

 by Mr. Coale at Davis Station. 



154. GENUS HELINAIA AUDUBON. 



*255. (638). Helinaia swainsonii AUD. 



Swainson's Warbler. 



Adult. Above, crown and nape, reddish-brown; rest of upper parts, 

 including sides of neck, olive; rump, wings and tail, tinged with 

 brownish; buffy or whitish stripe over the eye; below, creamy; sides, 

 olive, or grayish. Young, First Plumage. Wings and tail, like adult, 

 but other upper parts, including crown and nape, also throat and 

 breast, dull cinnamon-brown. 



