337 
1921 .] Recently published Ornithological Works. 
who was for some time stationed on Laysan Island, an 
outlier of the Hawaiian Islands, gives us some information 
on the nesting-habits of two rare Petrels— Pterodroma 
hypoleuca and Oceanodroma tristrami. 
As showing the effects of untimely weather, Mr. E. R. 
Warren tells us of the effects of a snow-storm at Colorado 
Springs on the 5th of May, when eight inches of snow 
covered the ground and did much damage to the migrants, 
who were then arriving and passing 111 great numbers. 
A 11 obituary notice of a young collector, Mr. M. P. 
Anderson, who accidentally met with his death in a ship¬ 
yard at Oakland, near San Francisco, in February 1919, 
where he was patriotically doing war-work, is of interq^t to 
English naturalists, as it was Mr. Anderson who was chosen 
some years ago to conduct the collecting expedition of the 
Duke of Bedford in eastern Asia, and all the birds and 
mammals then collected are now in the British Museum. 
The volume for 1919 contains descriptions of two new 
races, both from Lower California, by Mr. H. Oberholser— 
Junco oreganus pontilis and Pipilo fuscus aripolius. 
The 1920 volume contains three articles of general in¬ 
terest by Mr. A. Wetmore. In the first of these he suggests 
that the plug of feathers nearly always found in the pyloric 
diverticulum of the stomach of the Grebes acts as a strainer 
to prevent the passage of larger particles of bone or fish- 
scales from the stomach into the intestines. In another 
paper, as the result of observations 011 a young Great Blue 
Heron, he believes that the mysterious powder-down patches 
in the pelvic and pectoral regions of Herons and some other 
birds are used by the younger birds to oil and dress the 
contour feathers of the body, especially as the uropygial 
gland, often used later in life, develops slowly, and does not 
become functional till subsequently. 
Mr. Wetmore's third article deals with the wing-claw in 
the Swifts. Out of some 48 species belonging to the genera 
examined, he found the claw absent only in a few species of 
Callocalia , though often minute and rudimentary, and 
obviously of no functional importance. In the genus 
