384 
Letters , Extracts, and Notes. 
the coasts and do not split up into pairs. Based upon the 
above data I have elsewhere put forward the hypothesis that 
the birds were immature (vide ‘ Naturalist/ 1909, pp. 84, 85). 
Here I hope further to strengthen this hypothesis by direct 
objective evidence obtained from an examination of the 
plumage-markings. The rich variegated markings of chest¬ 
nut, brown, and black, which appear on the head, neck, 
breast, back, and wings, are found in the summer plumage 
in Sanderlings in all ages, after the first winter plumage. 
It is generally known as the nuptial plumage. When, how¬ 
ever, the tertials of those birds which tarry with us till late 
June, July, and the beginning of August are examined, it may 
be noticed that they, like the tertials of the first winter 
plumage , are relatively short, the longest not reaching to the 
tip of the fourth primary feather, the wing being folded in 
the natural position. By far the majority of Sanderlings 
which I have collected in late spring and summer have short 
tertials, and to such plumage I give the name of pre-nuptial, 
from its close resemblance to the true nuptial plumage which 
it precedes. But a few specimens collected towards the end 
of April and in early May, from small flocks, shewed on 
examination to have longer tertials which reached halfway 
between the tip of the fourth and third primary, and in some 
cases almost to the tip of the third primary. Such birds, I 
believe, have assumed the adult nuptial plumage of the second 
or subsequent springs. This plumage follows the plumage 
of the second or subsequent winters, in which the long ashy- 
grey tertials are easily distinguishable from the darker 
shorter ones of the first winter plumage. 
The Annual General Meeting of the B. 0. U .—We are 
requested by the Secretary to state that the Annual General 
Meeting, for 1910, of the British Ornithologists' Union will 
be held at the Zoological Society's Offices, 3 Hanover Square 
(by permission), on Wednesday, May 25th, at 5.30 p.m. The 
usual dinner after the meeting will take place, in conjunction 
with the monthly meeting of the British Ornithologists' 
Club, at Pagani's Restaurant, 42 Great Portland Street, 
at 7 p.m. 
