482 General Notes. es 
In the season of 1910 there were two pairs of which the males were 
Golden-wings, the females Brewster’s; one pair of Golden-wings; and one 
unmated male Brewster’s. The issue of one of the heterogeneous pairs, 
Golden-wing and Brewster’s, were all Brewster’s Warblers, of the other, 
a mixed brood of Golden-wing and Brewster’s. The pair of Golden- 
wings produced Golden-wings only. 
In 1912 a male Golden-wing mated with a female Brewster’s. 
In 1913 a male Golden-wing mated with a female Blue-wing, a male 
Brewster’s with a female Golden-wing. The progeny of the first pair 
were all Brewster’s, of the second pair one Golden-wing plus several 
Brewster’s. 
In 1914 a male Brewster’s mated with a female Golden-wing; their nest 
was not discovered till June 16, the day the young left it. 
In 1917 a male Brewster’s mated with a female Golden-wing. Here are 
six cases of the mating of Brewster’s Warbler, each time with a Golden- 
wing, and one case of a Blue-wing mated with a Golden-wing. Observe 
that all previously published accounts of the pairing of Brewster’s Warbler 
have been records of the union of this form with either a Golden-wing or 
a Blue-wing (see my paper in Mem. Mus. Comp. Zoél., Vol. XL, No. 2, 
pi 71). 
It is worthy of note that the numerous Golden-winged and Brewster’s 
Warblers seen in this locality during these years have without exception 
exhibited an absolute purity of plumage in spite of the constant crossing 
of the two forms. In other words, no plumage intermediate between the 
Golden-wing and Brewster’s has cropped out. 
Duration of the nestling period: in 1897 the five eggs in a nest belonging 
to a pair of Golden-winged Warblers (Arlington, Mass.) hatched June 8, 
the young left the nest June 15. In 1910 the five eggs of a Brewster’s 
Warbler mated with a male Golden-wing hatched June 8, the young left 
the nest June 17. In 1917, the five eggs of a Golden-wing mated with a 
male Brewster’s Warbler hatched June 21, the young left the nest June 
29-30. The life of the young birds in the nest therefore covers from seven 
to ten days. 
The spring of 1917 was without precedent in its backwardness. V. 
chrysoptera did not arrive until May 19. This is latest date for the arrival 
of this bird in my records of twenty-eight years, the average time of 
arrival being May 11-12, the earliest, May 3 (1905). This will account 
for the phenomenally late breeding of the 1917 birds given above. 
Several other localities in the town of Lexington are the home of Golden- 
winged Warblers, but none of them have ever yielded a Brewster’s Warbler. 
In the adjacent towns I have twice seen a Brewster’s Warbler: in Concord, 
May 19, 1912 (Faxon, Mem. Comp. Zoél., Vol XL, No. 6, p. 312, footnote 
1), five miles from the Lexington swamp, and in Waltham, May 31, 1915, 
two miles from the Lexington locality— Watrer Faxon, Lexington, 
Mass. 
