Aptosochromatism. 
A Tabulated Field Study. 
BY WALTER IIOXIE, FROGMORE, S. C. 
The following table was made at Bull’s Point, 
Apr. 23rd, 1886. The specimens examined were 
Dunlin. It was my intention at the time to 
make a similar study of those other species of 
Shore-birds — the Knot, Sanderling and Black- 
breasted Plover, but I failed to obtain a suffi- 
cient number of specimens any one time. I 
now offer this table for publication together 
with an explanation of the method used in 
making it up. And I hope I may receive from 
some of my co-workers a little more aid this 
season than 1 did last, upon this line of investi- 
gation. 
I first took twelve specimens of Duplin and 
numbered them in sequence according to the 
blackness on the breast. No. 1 was very dark 
and No. 12 in almost typical winter dress. 
This column I headed Black. The second col- 
umn marked “p. f.” is intended to show the rel- 
ative amount of “pin feathers” on the speci- 
mens — No. 1 having the most and No. 12 the 
least. Between the last four it was quite diffi- 
cult to decide with positive exactness. Upon 
finding that No. 4 was at the head of the list, 
and that the tips of the pin feathers showed no 
white , I made a final note on the back of the 
tag “R. o. t.,” which was to signify that on 
dissection I expected to find the reproductive 
organs large. That is probably larger than in 
some of the specimens above it on the list. 
Next I skinned and dissected my specimens, 
!j placing the number in the first class upon 
each. I now placed the males and females in 
! separate classes, giving them new numbers but 
still in accordance with the sequence of “JRacfc” 
Nos. Lastly I placed the reproductive organs 
in their order of size. The order in which they 
now stand is indicated in the columns marked 
“S. of O.” It will now be seen that among the 
females there is no break in the sequence of 
numbers. Among the males a probable note 
was made previous to dissection, which ac- 
counts for any discrepancy and the close simi- 
larity of specimens 11 and 12 gave me no cause 
for disappointment when I found that my last 
column would not quite “hitch” at the bottom. 
Birds from Fort Churchill, Hudson's AUK, VII, Oat;, 
Bay, W.Bagle Clark, 1890,p„ 3 21 
Tringa alpina pacifica. — a, b, adults in summer plumage. These 
specimens seem to agree perfectly with Scotch specimens of Trtiiga 
alpina , with which they have been compared. After an examination 
of the few American specimens of this bird at my disposal I have come 
to the conclusion that even the eastern American Dunlins are liable to 
considerable variation. An adult specimen from New Jersey in full 
summer plumage is much brighter, though paler, in color than any Euro- 
pean specimen I have seen ; and the breast is whiter and much less streaked 
with dusky; the bill, however, is only 1.30 inches in length. An adult 
in full winter plumage, and also from New Jersey, is a deep brown on the 
upper surface and quite different from the European bird at the same 
season, and the bill is no less than 1.70 inches in length. The various 
dimensions of these four specimens are as follows : 
W 171 g 
Culmen 
Tarsus 
Pi ■ 
Fort Churchill a 
4-57 in- 
1.43 in. 
.97 in. 
' ";/ r 
Fort Churchill b 
4-65 “ 
1.52 “ 
1.02 “ 
New Jersey (summer) 
4-65 “ 
1.30 “ 
.96 “ 
New Jersey (winter) 
4-8s “ 
1.70 “ 
1.06 “ 
1 have not seen any specimens of Red-backed 
Sandpipers ( Pelidna alpina americand) , in lull 
adult plumage in the fall, the first arrivals 
wearing mostly adult plumage, but as I have f 
been informed by gunners that they have shottf 
specimens in full adult plumage in the fall, I 
cannot make a single exception as yet of our 
New England shore birds not retaining their 
adult plumage in the fall. 
respondents on this subject, the plumage of our 
Limicolce. „ or _ 
O.&O.XII. Do. . 1887 P. 
£ . CLiurr* 
DUNLIN. 
April 23rd, 1886 
Black. 
P. F. 
Female. 
Male. S. of 0. 
1 
2 
1 
i 
2 
12 
i 
2 
3 
6 
2 
3 
4 
1 
3 
1 
5 
3 
4 
2 
4 
2 
4 
77. y. 
7 
11 
5 
5 
Ina alpina sakhalina. Red-backed Sandpiper. — Appeared Sept. 
8 
5 
3 
3 
straggled along until Oet. 27, never more than two or three being 
9 
8?\ 
6 
6 
gether. 
10 
7? j 
4 
4 
11 
9? 1 
7 
8 
AUk 27. July -1910 p, 3PJT 
l b.&o 
Jul. 1887 
8 
p> iOl-IOZ. 
7 
*9 
