Fatio on the Forms and Colours of Plumage. 377 



frequency of these meteors in different months. The meteor of Nov. 22, 1862 

 (with a sketch) is described by Mr. E. J. Lowe, vol. ii., p. 422. Remarkable 

 Detonating Meteors of Feb. and Nov., 1865, are described by Mr. Herschel, 

 vol. ix., p. 99. The " Herschel-Browning Spectroscope," is figured in the article 

 called The Coming Meteoric Shower — Spectra of Meteors, Aug. number (1866), 

 p. 38. In the last paragraph but one of this article, read gaseous matter 

 instead of "porous." This paper contains important extracts from Mr. 

 Herschel's lecture at the Royal Institution. The October number (1866) com- 

 mences with a most important paper by Mr. Herschel on the Prismatic Spectra 

 of the August Meteors, illustrated by a coloured plate. 



FATIO ON THE FOKMS AND COLOURS OF PLUMAGE. 



M. Victoe Fatio lias kindly sent us a copy of his important 

 paper on " the Different Modifications in the Form and Colour- 

 ation of Plumage,"* of which we shall proceed to give an 

 account, with extracts from the more important passages. 



Speaking of the down first developed in birds, M. Fatio 

 says, " In the thickness of the skin, on a growing bulb, and 

 in the place of the future feather, the down grows and developes 

 itself in a manner analogous to that which we shall presently 

 study in the feather. It moves on little by little as it grows 

 through the cutaneous layers, and at last pierces the surface 

 in the form of a hairy looking material, ordinarily composed of 

 eight to twelve, and sometimes of as many as twenty-four distinct 

 filaments. This down does not always possess a stem and central 

 axis like the barbs of a feather, and resembles those barbs which 

 are held together by the extremity of a small special sheath. Down 

 not only belongs to a young age, for we find it as a protecting 

 covering of adult birds, whether garnishing the base of the 

 stems of nearly all feathers, as a material without axis, at the 

 base, and in the middle of the principal stem, or lastly when 

 arranged on a separate stem, isolated and developed in the 

 single tube of the principal feather, and lining to a greater or 

 less extent its internal surface. This arrangement constitutes 

 the double feathers of our Gallinaceous birds, and of our birds 

 of prey, and is seen in the triple feather of the cassowary of 

 the Indian Archipelago." 



M. Fatio enumerates three sorts of down — cutaneous down, 

 basilar, and feather down. The first is directly attached to the 

 skin, the second confined to the basal portion of the feathers, 

 and the third to the principal stem at the sides of downy 

 feathers. The barbs in these downs vary a little in form, but 



* Des Diverses Modifications dans les Formes et la Colouration des Plumes, par 

 Victor Fatio. (Tire du Memoires de la Societe de Physique a d'Histoire N aturelle 

 de Grenieve, tome xviii, 2me. partie.) 



