The Microscope. 101 



posterior series, tlie former bearing hamuli and cilia, while the 

 posterior has cilia alone. The curvature of the downward ex- 

 pansion of the barb is uniformly toward the row on which the 

 hamuli are found. 



The difference in the degrees of elevation of the two series of 

 barbules on the sides of the barbs as shown by figure 3, is as 

 marked as its purpose will be evident when the relations of these 

 series to eacli other are considered. Fig. 4 is a more highly 

 magnified delineation of an anterior barbule, showing distinctly 

 the two forms of barbicels, hamuli and cilia, while Fig. 5 shows 

 the adaption of the two series to each other. 



EXPLANATION OF FIGUEES. 



Fig. 1. The anterior side of a barb from the primary of a domestic pigeon, 

 ■with its barbules cut oH'close to the raehij^ett wliich rises distinctly above thenx; 

 lueneatli them the i)ith-(ells, below which the transparent, liorny exterior of 

 the barb is seen. 



Fig. 2. A barb from another species, with the anterior barbules removed 

 showing no elevation of the superior rachisett and a broader velhim below the 

 pitii-celis. 



Fig. 3. A transverse section of a barb with its barbules in position, the an- 

 terior being the more elevated and bearing both hamuli and cilia, while the 

 posterior and lower bears cilia only. 



Fig. 4. A barbule with its armature of l)arbicels of both kinds, greatly 

 magnified. 



Fig. 5. Two series of barbules in their relations to each other iit. liitu, the 

 anterior overlying the posterior, thus iorming the meshes of a web, the bar- 

 bicels being concealed. 



Fig. tt. An exaggerated delineation of the fnnbriated border of the vellum 

 of H primary barb ; of exceptional occurrance apparently. 



Fig. 7. ()utline of a barb from a feather found in tlie crest of a Kingfisher 

 showing barbules of a remarkable type. 



Fig. 8. A barbule from a barb of a long feather in the Peacock's tail. Ex 

 cept the crude ciliation at the extremity it bears no resemblance to any ele- 

 ment of true feathers, being comparatively nonelastic, and apparently chiti- 

 ous in composition, yet rivaling the elytra of the famous Brazilian beetles in 

 the iridescence of its changeable reflections. 



A MICROSCOPICAL STUDY OF SOME INGREDIENTS OF 

 THE SPUTUM. 



WILLIAM B. CANFIELD, A. M., M. D., 

 LEOTUHKR ON HISTOLOGY, AND CHIEF OF CHEST CLINIC, UNIVERSITY 



OF MARYLAND. 



THE microscopical examination of the sputum or products of 

 expectoration is not always agreeable, but it yields often such 



