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arriving at Saint Louis the next day. This wave was the culmination 
of six days of constantly increasing warmth, and started the birds be- 
fore it had reached its maximum. April 25, first arrivals were reported 
from latitude 41° 22’ in Nebraska, and April 26 an increase of summer 
residents, with the first flock of transients, was recorded at Saint Louis— 
at both places the day before the maximum of temperature. The night 
of the maximum (April 27) brought “ firsts” to latitude 399 43/ and lati- 
tude 40° 08/ in Illinois. A record was made at latitude 42° 16/ in Illi- 
nois on April 28, but as this was the day after a quite pronounced polar 
wave it is probable that the birds came the day before with the maxi. 
mum wave, and had escaped observation. The same remark applies 
to two records from latitude 40° 47’ and 40° 53’, April 28 and 29, which 
probably belong to April 26. The largest wave of the season began 
at Custer, Mont., April 28, passed Yankton and Saint Paul, and ex- 
tended down the Mississippi to Saint Louis on the 29th, and reached 
the Lower Mississippi Valley on the 30th. As in the case of the previ- 
ous wave, a slight bird movement took place the day before, bringing 
the first Kingbird to latitude 39° 14’ in Missouri, the bulk to latitude 
399 43/ in Illinois, and flocks of transients to latitude 38° 40/ in Missouri. 
But the next night witnessed the grand movement, which carried the 
species to latitude 41° 05’, 419 26’, 419 38’, 41° 40’, and 42° 37’ in Iowa, 
and latitude 39° 16’, 41° 36’, 41° 46’, 41° 58’, and 42° 37’ in Illinois. 
Hence it appears that between darkness and daylight there was a solid 
advance of Kingbirds over 200 miles of territory. Who shall say how 
many, many thousand were winging their way northward through the 
silent watches of that night? The notes of May 1 from latitude 41° 14/ 
jn Iowa undoubtedly also belong tothis wave. The night of May 1 was 
cold throughout the northern half of the Mississippi Valley, and was 
followed two days later by a warmer period, which marked another ad. 
vance of Kingbirds to latitude 43° 06’. In this wave there was no such 
uniformity of movement as in the preceding. Indeed, out of the seven 
notes which have been apportioned to it, only two hit the maximum 
exactly; but considering them all to pertain to this wave, the advance 
is found to be at latitude 43° and 43° 06’ in Wisconsin, and latitude 43° 
43’ in Minnesota, with the bulk at latitude 39° 12’ in Illinois and lati- 
tude 419° 14’ in Iowa. The culmination of the next wzve extended from 
May 8 in the northwest to May 10 in the southeast. During the five 
days of preparation for this wave there were no notes. On the day 
preceding, the bulk arrived at latitude 42° 56’ in Dakota; the first at 
latitude 44° 22’ in Wisconsin and at latitude 45° in Minnesota, while 
on the day of the maximum “ firsts” were recorded at latitude 43° 43’ 
and 44° 30/ in Wisconsin, latitude 44° 32’ in Minnesota, latitude 38° 
55/ in Kansas, and latitude 47° 08’ in Dakota, with new arrivals of bulk 
at latitude 43° 06’ in Wisconsin and 41° 36/ in Towa. Thus there was 
nearly as much real advance during these nights as during the last 
wave of April, the difference being that the April wave spread over all 
