JANUAET 6, 1911] 



SCIENCE 



39 



the fresh fall plumage the red is of a dull 

 pinkish hue (burnt carmine) ; there is there- 

 after a progressive change, slow in autumn, 

 rapid in spring, until the breeding season 

 finds the amorous males, bubbling with song, 

 and going through various courting antics, 

 arrayed in brilliant poppy red. 



A nuptial attire has been donned, in the 

 male only, but there has been no replacement 

 of feathers; nor has there been an influx of 

 new pigment into the feather as a former 

 most unsound theory presupposed. 



Microscopical examination of various feath- 

 ers appropriately selected during the period 

 of molt, when old and new feathers are to 

 be found side by side, discloses the following 

 facts : In the newly acquired, unworn plu- 

 mage, the red pigment is restricted to the barbs 

 of the contour portion of each feather, ex- 

 cept for their terminal portions to a distance 

 of one millimeter from their tips. These 

 barb ends, which thus together constitute a 

 band terminating each feather, and all the 

 harbules, are white. In the extremely old, 

 abraded (spring and autumn) feather these 

 grayish white end portions of the barbs in the 

 overlapping feathers, and all the barbules, 

 have simply been broken off through attrition 

 and lost, thus removing the grayish obscura- 

 tion, and disclosing the bright red of the 

 barbs, the tone of which has not in fact 

 changed one whit. 



Thus wear alone has accomplished the 

 nuptial brightening of dress. A difference of 

 structure is evident between the pigmented 

 and unpigmented portions of the feather, the 

 former being by far the most resistant, the 

 latter being so adjusted in extent and texture 

 as to become disintegrated and lost at the ad- 

 vent of the season of mating. 



The production of color in the growing 

 feather in August is thus clearly anticipatory ; 

 and we observe here manifestation of a most 

 delicate structural complex, so balanced as to 

 bring about through purely extrinsic, physical 

 agencies, a conspicuous brightening of plu- 

 mage at the season of reproduction, seven to 

 nine months later. 



The chief point to which I wish to fix atten- 



tion is, that the brilliant hue of the nuptial 

 dress is thus in reality acquired at the post- 

 nuptial (or annual) molt, several weeks after 

 the season of mating, instead of immediately 

 preceding. This fall molt period is generally 

 considered (as by bird fanciers and poultry 

 raisers) to be the season of the year when the 

 vitality of the bird is at its lowest ebb. 

 Moreover, the organs of reproduction are at 

 this time much reduced in size, and certainly 

 quiescent in function. It would seem, there- 

 fore, that the production of the brilliant 

 nuptial plumage in the linnet (and similar 

 sequence of processes and results is well 

 known to occur in many other passerine 

 birds') is not directly associated with a period 

 of excessive sexual vigor, as a current theory 

 postulates. 



J. Grinnell 

 Museum of Veetebbate Zoology, 

 Untvebsitt of Califobnia 



THE OKLAHOMA ACADEMY OF SCIENCE 



The academy held its second annual meeting at 

 the State University at Norman, November 25-26. 

 In spite of the fact that this was only its second 

 annual meeting, about forty papers were read, 

 among which were the following: 



" The Human Tonsillar Band as a Protective 

 Organ," Dr. J. D. McLaren. 



" Study of Lipase," H. I. Jones. 



" The Physical and Chemical Changes in the 

 Burning of Clays," L. C. Snider. 



" The Road Material of Oklahoma," L. C. 

 Snider. 



" The Future Sources of Power in Oklahoma," 

 C. N. Gould. 



" A Brief History of Oklahoma Geology," C. N. 

 Gould. 



" Comparison of the Four Mountain Uplifts in 

 Oklahoma," C. N. Gould. 



"The Oklahoma Redbeds," C. N. Gould. 



" The Ecology of the early Juvenile Life of the 

 Unionidae," F. B. Isely. 



" The Unionidie of the Red River Drainage- 

 System," F. B. Isely. 



" Notes of the Experimental Study of the 

 Growth and Migration of Mussels," F. B. Isely. 



'■ See, especially, Dwight, Annals N. Y. Acad^ 

 8ci., Vol. XIII., 1900, pp. 73-360. 



