Bird Migration in the Mississippi Valley. 13 



while on the 15th it continued northwest until the evening of the six- 

 teenth, with cool nights. 



The theory is that the transients were overtaken by the rainstorm of Sun- 

 day (13th) night, and kept back by the cool nights following. Since the 17th 

 we have had warmer weather with southerly winds, and the transients 

 have thinned out decidedly. The best days were the fourteenth, fifteenth 

 and sixteenth. There is no doubt but some birds were suddenly stopped. 

 Water thrushes, Lincoln's finches, yellow-bellied fly-catchers, etc., were found 

 in a dry pasture in the city, and the short-billed marsh wren by the way- 

 side. 



May 21. Yesterday was one of those hot days with southwind, and little 

 could be done. Last night copious rains, to-day a sultry, threatening south- 

 west wind. Look out for a grand move. 



May 29. Cool weather continues up to this day, but two warm nights, the 

 23d and 24th, have taken off all transients. Migration for this Spring is at an 

 end. 



