Nov., 1908 NESTING OF THE PINE SISKIN AT GREAT SLAVE LAKE 235 and we were compelled to run on the lee side of Moose 'Island, and wait for the wind to subside. Moose Island is a high, rocky, stony island, about one and one- half miles long and three-fourths of a mile wide, a few miles from Fort Resolution, at the south-west corner of Great Slave Lake. The island is fringed with white spruce of good size; but the interior is high and rocky, covered with a tangle of burned and fallen spruce timber and sprinkled over with a sparse growth of young poplars. A few Pine Siski?s were seen in the spruce trees as we landed, and a few Chip- ping Sparrows (Spizella passerna) along the shores. The interior of the island revealed many Slate-colored Juncos (./unco ,?yemalis) and Intermediate Sparrows ( ?7onotrichia 1. gambeh'), one Black-poll Warbler's (Zlendroica striata) nest with four eggs, one Sparrow Hawk, one Canada Jay (Perisoreus canadensis),and a small Flycatcher (Empidonax). White-throated Sparrows were fairly common, and a Spotted Sandpiper's (Actiris macularia) nest with four eggs was observed on the north shore of the island. H'alf a dozen Pine Siskins were observed at one time in the tops of spruce along the south shore. After lunch I was resting under a white spruce, about one foot in diameter, near our campfire on the lake shore, when I saw a Pine Siskin fly into the tree directly above my head. Examining?the tree carefully I soon saw the nest among the lower limbs of the tree, about fifteen feet from the ground, near the end of a small horizontal branch about two feet from the trunk of the tree. Both parent birds were about, and I shot the nearest, which proved to be the male. The other bird was unfortunately lost in the brush. The nest contained three eggs, advanced in incubation; very pale blue in color, sparsely spotted at the larger end with light reddish brown. One of the eggs had on one side, near the smaller end a heavy comma-shaped streak about one-fourth of an inch long, and one other egg had a heavy, irregular line about the same size in a similar position; these streaks were deep umber-colored. The other egg had no large marks. The eggs also showed a very few minute black pinpoint marks at their larger ends. The nest was very neatly built, well-cupped and well-concealed by the very thick terminal twigs of the white spruce branch. Depth (outside), two and one- half inches; (inside) one and one-half inches. Diameter (external) two and one- half inches; (internal)one and one-half inches; composed of small dead spruce twigs, a few grass es, fibrous bark shreds, and a few shreds of cottony substance; lined with fine grass fibers and hair, mixed with a few bunches of moss fibers. Herschel ?rsland, 2V. W. 7'. MR. ROCKWELL'S SUGGESTION OF COOPERATION IN ORNI- THOLOGICAL STUDIES By WILLIAM E. RITTER I WAS interested in Mr. Rockwell's "Plan for Cooperative Ornithology" printed in the September Co?)oa. A word should be spoken on this subject from the standpoint of general biology as well as from that of ornithology. That there are more observers of the natural habits of birds than of any other group of animals is, I suppose, beyond question. As a result there is more accur-
