The Microscope. 137 



•of which we will examine somewhat minutely. Take one, for 

 example, from the breast of the swan and while each element 

 of the type is recognized at once, we find every one of them 

 ■differing from it so much as to suggest a new form of structure, 

 yet it is merely a modification of each to meet the demand for 

 contour and incidentally other purposes. 



Notably the calamus is shorter, softer, more elastic ; the barbs 

 of the superior umbilical section are fragile, knobbed near the 

 base, beyond which the knobs are developed into lateral spines 

 to the extremities, and without changing the arrangement of the 

 barbicels in rows along the superior angle, the rounded, fluffy 

 form is obtained by the flection of certain ones in the flattened 

 portion, so as to point those spined filaments outwardly in every 

 direction. 



This arrangement of the plumage extends some distance along 

 -the shaft from the umbilicus when the barbs begin to be more 

 •compacted, flattened at the base into curved, lamillated, linear 

 expansions, followed a short distance by modified barbicels the 

 ■cilia and booklets of which commence to form a frail web that 

 extends with each successive barb until the series expands into a 

 leaf-like form, beyond which the barbs are continued as double- 

 ;spined, floating threads to great length, terminating with spines. 



Thus by changing the arrangement and form of the barbules 

 and barbicels never so little, if abruptly, patterns of beautiful 

 -outline in great variety are obtained, to which if are added tints 

 of colors in the barb and barbule shafts, the most wonderful 

 revelations follow. The extension of the shafts of these divisions 

 of a feather into long flexible filaments, invisibly spined perhaps, 

 soften the plumage of a bird, or of a given tract of it, into con- 

 tour and lines of indescribable fascination. On the other hand 

 abbreviation [of these portions, even the omission of one vane 

 and wide separation of those on the opposite with high coloring, 

 rgives us instances of the most resplendant plumage, as found in 

 the case of the Lyre Bird and many others. In the crest of the 

 Kingfisher (C alcyon) so common to our lakeshores and clear, 

 limpid streams, we find long, narrow feathers with the arrange- 

 ment of the barbs and barbules such as to make them almost 

 indistinguishable from the antennas of some of the larger moths, 

 when under a magnification of about 160 diameters 



Fig. 7, gives an outline of one such. The scattering barbules 



