98 The Microscope. 



€8t without leading us irresistably to their minute analyses. A 

 passing bird, a falling snowflake, or the immaculate purity of sl 

 flower may arrest the attention of the casual observer, but will 

 not awken the enthusiasm characteristic of one who has tasted 

 the pleasures of microscopical research in the optical investiga- 

 tion of Nature's wonderful revelations. One whose authority 

 has universal acceptance in all Christian lands, has said that 

 Solomon in all his glory was not arrayed like the lily, yet one of 

 its petals under the proper lens when beheld by well-trained eyes 

 will not less surprise by the revelations of its structure. 



The graceful swan immortalized in mythology and in song, 

 reveals more that is wonderful in a feather thus viewed, than in 

 itself as a whole as ordinarily observed. This is true of most 

 birds, strange as may seem the apparent solecism, yet in con- 

 sideration of the circumstances under which the\'' are seen, noth- 

 ing is assured, and what may be said of the wonder revealed in 

 the microscopic elements of a feather may be said with no less 

 emphasis of their adaptations to their uses in the economy of the 

 entire plumage. To make this evident a brief description of a 

 typical feather will first be given. 



It consists of a stem, the lower position of which is horny, 

 naked, and cylindrical, called the calamus or barrel ; the upper 

 and longer portion which tapers symmetrically to a point, is the 

 rhachis, or shaft, and is squarish, horny externally, and filled 

 with light, compact pith-cells. At the junction of these two 

 divisions interiorly is a depression called the superior umbilicus 

 from a little below which arises the hyporchachis, or after-shaft. 

 The inferior umbilicus consists of the opening in the dermal end 

 of the calamus through which the nourishment of the feather is 

 maintained. Commencing at the superior umbilicus there ex- 

 tends on each side of the shaft a vane or vexilla, composed of a 

 series of flat, lanceolate, appressed barbs springing from the 

 superior, or external angle of the shaft. Between these vanes 

 inferiorly, begining at the umbilicus, there is an obtuse-angled 

 groove extending to the «apex of the shaft. The barbs are re- 

 latively broad at their base, narrowing to an acute point at the 

 extremity and bearing barbules along the external borders of the 

 shaft. The barbules are to the barbs what the barbs are to the 

 primary shaft, and in turn bear on their inferior border, after an 

 expansion like that of the barbs, a series of less compacted 



