The wishbone, called a furcula, is the fusion of two collarbones at the sternum.    From Wordnik.com.  [Livescience.com] Reference

I took 2 photos of it before it deployed its furcula and disappeared into thin air.    From Wordnik.com.  [Springtail before it sprung away] Reference

Mucrones: in Collembola the two small end pieces of the furcula, proceeding from the dentes.    From Wordnik.com.  [Explanation of Terms Used in Entomology] Reference

Snow fleas, like all springtails, have an unusual appendage (a furcula) that folds under the abdomen and can be used to suddenly propel the insects several inches.    From Wordnik.com.  [Rich Wolf: Boulder's Heart-Warming Fleas] Reference

But Archaeopteryx was very likely capable of powered fligh sic judging from its relatively massive furcula and the asymmetric rachis of its primary flight feathers Feduccia and Tordoff 1979; Olson and Feduccia 1979.    From Wordnik.com.  [Experts in creationism trials -- Shallit be? - The Panda's Thumb] Reference

The extremities of the furcula, where articulated to the coracoids, vary considerably in outline.    From Wordnik.com.  [The Variation of Animals and Plants Under Domestication, Vol. I.] Reference

When they want to move, they release their spring-loaded furcula, launching themselves into the air.    From Wordnik.com.  [Durangoherald.com] Reference

In a pouter, the furcula had not been lengthened proportionally with the increased length of the body.    From Wordnik.com.  [The Variation of Animals and Plants Under Domestication, Vol. I.] Reference

The size and shape of the perforations in the sternum, and the size and divergence of the arms of the furcula, differ.    From Wordnik.com.  [The Variation of Animals and Plants Under Domestication, Vol. I.] Reference

The size and shape of the apertures in the sternum are highly variable; so is the degree of divergence and relative size of the two arms of the furcula.    From Wordnik.com.  [On the Origin of Species by Means of Natural Selection or the Preservation of Favoured Races in the Struggle for Life. (2nd edition)] Reference

This reduction of the crest in all the breeds probably accounts for the great variability, before referred to, in the curvature of the furcula, and in the shape of its sternal extremity.    From Wordnik.com.  [The Variation of Animals and Plants Under Domestication, Vol. I.] Reference

The arms of the furcula in all the specimens which I compared, diverged less, proportionally with the size of body, than in the rock-pigeon; and the whole furcula was proportionally shorter.    From Wordnik.com.  [The Variation of Animals and Plants Under Domestication, Vol. I.] Reference

We thus clearly see that the sternum, scapulæ, and furcula are all reduced in proportional length; but when we turn to the wings we find what at first appears a wholly different and unexpected result.    From Wordnik.com.  [The Variation of Animals and Plants Under Domestication, Vol. I.] Reference

Thus in a runt, which measured from tip to tip of wings 38½ inches, the furcula was only a very little longer (with the arms hardly more divergent) than in a rock-pigeon which measured from tip to tip 26½ inches.    From Wordnik.com.  [The Variation of Animals and Plants Under Domestication, Vol. I.] Reference

To sum up: we may confidently admit that the length of the sternum, and frequently the prominence of its crest, the length of the scapulæ and furcula, have all been reduced in size in comparison with the same parts in the rock-pigeon.    From Wordnik.com.  [The Variation of Animals and Plants Under Domestication, Vol. I.] Reference

In fig. 29, B and C represent the furculæ of two fantails; and it will be seen that the divergence in B is rather less even than in the furcula of the short-faced, small-sized tumbler (A); whereas the divergence in C equals that in a rock-pigeon, or in the pouter (D), though the latter is a much larger bird.    From Wordnik.com.  [The Variation of Animals and Plants Under Domestication, Vol. I.] Reference

In the following discussion on the relative proportions of the feet, sternum, furcula, scapulæ, and wings, I may premise, in order to give some confidence to the reader, that my measurements were all made in the same manner, and that all the measurements of the external parts were made without the least intention of applying them to the following purpose.    From Wordnik.com.  [The Variation of Animals and Plants Under Domestication, Vol. I.] Reference

The first rudiment of the larynx consists of two arytenoid swellings, which appear, one on either side of the cephalic end of the laryngo-tracheal groove, and are continuous in front of the groove with a transverse ridge (furcula of His) which lies between the ventral ends of the third branchial arches and from which the epiglottis is subsequently developed (Figs. 980, 981).    From Wordnik.com.  [XI. Splanchnology. 1. The Respiratory Apparatus] Reference

The shortening of the humerus and radius in the seventeen birds may probably be attributed to disuse, as in the case of the scapulæ and furcula to which the wing-bones are attached; -- the lengthening of the wing-feathers, and consequently the expansion of the wings from tip to tip, being, on the other hand, as completely independent of use and disuse as is the growth of the hair or wool on our long-haired dogs or long-woolled sheep.    From Wordnik.com.  [The Variation of Animals and Plants Under Domestication, Vol. I.] Reference

24 inches, therefore only 2½ inches less than the rock-pigeon, the furcula was barely two-thirds of the length of that of the rock-pigeon.    From Wordnik.com.  [The Variation of Animals and Plants Under Domestication, Vol. I.] Reference

Alius, fed fupra culraura furcula, infra a. IR 3.    From Wordnik.com.  [Lexicon vniversae rei nvmariae vetervm et praecipve Graecorvm ac Romanorvm cvm observationibvs antiqvariis geographicis chronologicis historicis criticis et passim cvm explicatione monogrammatvm edidit Io. Christophorvs Rasche] Reference