. Evenings at the microscope : or, Researches among the minuter organs and forms of animal life . Zoology; Microscopy; Microscopes. 16 EVENINGS AT THE MICROSCOPE. scope, we see that the central stem carries on each side a row of barbs, which interlock with each other. The mag- nifying power shows us that these barbs are not simple filaments, but are themselves doubly bearded in the same fashion; and further, that these little beards, called bar- bules, of the second series, are furnished with a third series. It is in this third series of filaments, called bar- bulets, that the tenacity in ques
. Evenings at the microscope : or, Researches among the minuter organs and forms of animal life . Zoology; Microscopy; Microscopes. 16 EVENINGS AT THE MICROSCOPE. scope, we see that the central stem carries on each side a row of barbs, which interlock with each other. The mag- nifying power shows us that these barbs are not simple filaments, but are themselves doubly bearded in the same fashion; and further, that these little beards, called bar- bules, of the second series, are furnished with a third series. It is in this third series of filaments, called bar- bulets, that the tenacity in question resides. If we isolate one of the primary beards, by stripping away a few on each side of it, and again put it on the stage, we see that the secondary barbules of one side are armed differently from those of the other side. Those of the lower side carry short and simple barbulets, whereas those of the side which looks towards the point of the feather bear much longer ones; and, moreover, many of them are abruptly hooked backwards. Now, whenever the primary beards are brought into contact, some of these hooks catch on the barbule next above, and, slipping into the angles formed by the barbulets, hold there, and thus the two contiguous beards are firmly locked together. In the beard of the goose-quill, the structure is essentially the same, but the barbulets are far more numerous and more closely set; they are also proportionally much larger—both those which are hooked and those which are simple. Indeed, the latter mani- fest a tendency to the hooked form, and by all these peculiari- ties the interlocking power is aug- mented. It is interesting to ob- serve the great expansion of the beard in a direction towards the interior surface of the feather towards the stroke, as I just now. BARE FROM Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrat
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