58 PROCEEDINGS OP THE 



April 1st, 2d, 6th and 20tli, and light ones on April 21st and 

 22d. The most sudden drops in temperature were fourteen de- 

 grees between April 5th and 6th, eleven between April I8th 

 and '9th, and eighteen between April 26th and 28th. 



The continued low temperature, April lst-l!)th, brought mi- 

 gration almost to a standstill, and undoubtedly backed up those 

 species that were ready to push northward. Rather higher tem- 

 perature on April 4th and 5th came too close after the warm 

 March weather to bring many migrants; nearly all the species 

 then due having already arrived. 



After the increasing temperature of Aprd lUtli migration was 

 at once apparent: 



New arrivals, Wave V 



April 21. Water Thrush. 



April 22. Catbird. 



April 23. Chimney Swift. 



The chief migrants April 20th-21st were Hermit Thrush, ar- 

 rived at 10 stations, Ruby-crowned Kinglet at 6, Yellow-palm 

 Warbler at 5. 



Then came the steady rise of 28° from April 19th-26th, which 

 brought a scattered arrival of birds from April 20th-23rd, and 

 an enormous increase April 25th-27th. This lieing followed by 

 the rise above mentioned, resulted in another wave April 30th- 

 May 1st, so that there were almost uninterrupted arrivals during 

 the last six days of the month, though fewer on the 2Stb and 

 29th owing to the drop in temperature on these days. 



New arrivals, Wave VI 



April 25. House Wren, WiLson's Thrush, Redstart, Black- 

 throated Blue Warlder. 

 April 26. Yellow Warbler, Rose-breasted Grosbeak, Solitary 

 Vireo, Wood Thrush, Maryland Yellowthroat, 

 Oven bird. 

 April 27. Kentucky Warbler, Worm-eating Warbler. 

 The conspicuous species were Barn Swallow, arrived at 9 sta- 

 tions April 26th-28lh, Brown Thrasher 15, Myrtle Warbler 10, 

 Black-and-white Warbler 14, Ovenbird 7, Chimney Swift 18, 

 House Wren 11, Maryland Yellowthroat 15. 



