Primary feathers were worn at the margins, with discontinuous barbules
between barbs, and the calamus was occasionally pinched.
If proper diagnostic feathers are present in a sample, it may be possible to use the microscopic characters in the downy (plumulaceous) barbules
to assign the feather sample to a particular group, order, or family of birds (Dove, 2000).
Each day of oviposition, the barbules
with the eggs attached were removed with fine-tipped scissors and placed on sheets of blue paper to facilitate observation of the eggs.
For that, they examined the fossilized barbules
- tiny, rib-like appendages that overlap and interlock like zippers to give a feather rigidity and strength.
A separate, striking amber specimen shows a birdlike feather branching into secondary twigs, or barbules
, with hook-lets like those in modern bird feathers that zip together side-by-side barbules
to make a tight, interlocked surface.
The bluebird's blue is called a "structural color," caused when light is scattered and reflected by tiny structures within each feather's myriad microscopic barbules
Ages later I let out that breath and the bird was still working, his dagger beak zipping up barbules
, oiling his sheen, completely unperturbed by us watchers or the noisy baptism.
15E), relatively short labium, widely darkened base and apex of the antennal segment II, subhyaline but always spotted hemelytron, ventral longitudinal keel on the male genital segment, barbules
on apical spine of the endosoma, 9-10 notches subtending the secondary gonopore (Fig.
Structural origin of the brown color of barbules
in male peacock tail feathers.
Perianth bristles 6, some of them longer than the achene, reddish or stramineous at the base, curved, finely and irregularly ciliatebarbate, the barbules
divergent to slightly ascendant on the upper part of the bristle and slightly retrorse at the lower part.
Cell structure of developing barbs and barbules
in down feathers of the chick: Central role of barb ridge morphogenesis for the evolution of feathers.
Histologically, barbs are formed by a mid-axial part called ramus from which barbules