°g ^n Jones, Bird Miff ration in loxva. \ \ <i 



times, coming from thickets like the first, but farther away from 

 sloughs, though not from water, since these woods are full of 

 pools of all sizes and depths. 



The soil of the St. Francis basin is a light sand, several feet in 

 depth, resting on a clayey subsoil. It is a peculiarity of the trees 

 of this region, especially the sweet gum {Licjiiidambar styraciflud) 

 to rot at the point where sand and clay touch. In this condition 

 the tree is easily blown over, and in its fall the roots take up the 

 surface soil, causing an excavation a few feet deep and several 

 yards wide, a convenient receptacle for the water, a miniature 

 pond with impermeable bottom. Such pools are scattered in 

 countless numbers throughout the woods on the higher levels, 

 while all depressions are naturally of a very swampy character. 



In such woods the Water Thrush is not confined to the water 

 courses as in other parts of Missouri, but is found in every part 

 of the wood ; so are the Prothonotary, the Parula, the Cerulean, 

 and apparently also the Swainson Warblers. It is here that th^ 

 Ovenbird, the Pipilo, the Blue-winged Yellow Warbler and the 

 Catbird are restricted to the oases of high ground, while the 

 Hooded and Kentucky Warblers, the Maryland Yellowthroat, and 

 especially the White-eyed Vireo, are at home and abundant on 

 high as well as on low ground, the two last named even in the 

 slough itself. 



From a week's tramp through the region I came to regard the 

 Swainson Warbler as a regular, though not common, denizen of 

 the swampy woods of Dunklin County, Missouri. 



RIRI) MIGRATION AT GRINNELL, IOWA. 



BY LYNDS JONES. 



I. Si'RiNd Mi(;k.'\tion. 



Ever since the inauguration of systematic study of bird 

 migration by Prof. W. \\'. Cooke in 1884, it has been my 

 purpose to collect sufficient data to determine the sequence of 

 arrival of the various migratorv birds at Grinnell, Iowa, where 



