Book VIL befides; but for a Sample, I fhall only infift upon the wonderful Provifion in the Bill for the judging of the Food, and that is by peculiar Nerves lodged therein for that Purpose; fmall and lefs numerous in fuch as have the Affiftance of another Senfe, the Eye; but large, more numerous, and thickly branched about, to the very Ends of the Beak, in fuch as hunt for their Food out of Sight in the Waters, in Mud, or under Ground (e). b And

And now if we compare the Organ and Act of Hearing, with those of Sight, we fhall find, that the Conclave is to Hearing, as the Retina is to Sight; that fonorous Bodies make their Impreffions thereby on the Brain, as vifible Objects do by the Retina. Alfo, that as there is an Apparatus in the Eye, by the opening and fhutting of the Pupil, to make it correfpond to all the Degrees of Light, fo there is in the Ear to make it conformable to all the Degrees of Sound, a noble Train of little Bones and Mufcles in Man, c. to ftrain and relax the Membrane, and at the fame Time to open and shut the Bafis of the Stapes (the fame as what I call the Operculum in Birds:) But in Birds, there is a more fimple, but fufficient Apparatus for this Purpofe, tender Cartilages, instead of Bones and Joints, to correfpond to the various Impreffions of Sounds, and to open and fhut the Operculum. Befides which, I fufpect the Ligament I mentioned, is only the Tendon of a Muscle, reaching to the inner Membrana Tympani, and joined thereto (as I find by a ftricter Scrutiny) and not to the Cartilage, as I imagined. By this Mufcle, the inner Membrane, and by Means of that the Outer alfo can be diftended or relaxed, as it is in Man, by the Malleus and its Mufcle, &c.

(e) Flat-billed Birds, that grope for their Meat, have three Pair of Nerves, that come into their Bills, whereby they have that Accuracy to diftinguish what is proper for Food, and what to be rejected by their Tafte, when they do not fee it. This was most evident in a Duck's Bill and Head; a Duck having larger Nerves that come into their Bills than Geefe, or any "other Bird that I have feen; and therefore quaffer and grope out their Meat the moft. But then I difcovered none of these Nerves in round-bill'd Birds. But fince, in my Anatomies in the Country, in a Rook, 1 firft obferved two Nerves that came down betwixt the Eyes into the upper Bill, but confiderably

Smaller

A

And now from the Head and Mouth, pafs we to its near Ally, the Stomach, another no lefs not able than useful Part; whether we confider the Elegancy of its Fibres and Mufcles, or its Multiplicity, one to foften and macerate, another to digeftor its Variety, fuited to various Foods, fome membraneous, agreeable to the frugivorous, or car nivorous Kind; fome mufculous and strong (f), fuited to the Comminution, and grinding of Corn and Grain, and fo to fupply the Defect of Teeth.

And now to this Specimen of the Parts, I might add many other Things, no less curiously contriv'd, made and fuited to the Occafions of thefe Volatiles; as particularly the Structure and Lodg

Smaller than any of the three Pair of Nerves, in the Bills of Ducks, but larger than the Nerves in any other round-bill'd Birds. And 'tis remarkable that these Birds, more than any other round-bill'd Birds, feem to grope for their Meat in Cowdung, &c. Mr. J. Clayton, in Philof. Tranfact. No. 206.

I obferv'd three Pair of Nerves in all the broad-bill'd Birds that I could meet with, and in all fuch as feel for their Food out of Sight, as Snipes, Woodcocks, Curlews, Geefe, Ducks, Teals, Widgeons, &c. These Nerves are very large, equalling almost the Optic Nerve in Thickness. Two are diftributed nigh the End of the upper Bill, and are there very much expanded, paffing through the Bone into the Membrane, lining the Roof of the Mouth. Dr. A. Moulen. Ibid. No. 199. Or both in Mr. Lowthorp's Abridg. V. 2. p. 861, 862.

(f) The Gizzard is not only made very ftrong, efpecially in the Granivorous; but hath alfo a Faculty of Grinding what is therein. For which Purpofe, the Bird fwalloweth rough Stones down, which, when grown fmooth, are rejected and caft out of the Stomach, as ufelefs. This Grinding may be heard in Falcons, Eagles, c. by laying the Ear clofe to them, when their Stomachs are empty, as the famous Dr. Harvey faith. De Generat. Exer. 7.

As to the Strength of the Gizzard, and the Ufe of Stones to the Digeftion of Fowls, divers curious Experiments may be met with, try'd by Seigneur Redi, with glafs Bubbles, folid Glafs, Diamonds, and other hard Bodies. See his Exp. Nat.

ment

ment of the Lungs (g); the Configuration of the Breaft, and its Bone, made like a Keel, for com→ 5 modious Paffage through the Air, to bear the large and strong Muscles, which move the Wings, and to counterpoife the Body, and fupport and reft it upon at rooft. The Neck allo might deserve our Notice, always either exactly proportion'd to the Length of the Legs, or elfe longer, to hunt out Food, to fearch in the Waters (b); as alfo to counterpoife the Body in Flight ().

And lastly,
I might

(g) It is no less remarkable in Birds, that their Lungs adhere to the Thorax, and have but little play, than that in other Animals they are loofe, and play much, which is a good Provifion for their steady Flight. Alfo they want the Diaphragm, and inftead thereof, have divers large Bladders made of thin transparent Membranes, with pretty large Holes out of one into the other. Thefe Membranes feem to me to ferve for Ligaments, or Braces to the Vifcera, as well as to contain Air. Towards the upper Part, each Lobe of the Lungs is. perforated in two Places, with large Perforations; whereof one is towards the outer, the other towards the inner Part of the Lobe. Through thefe Perforations, the Air hath a Paffage into the Belly, (as in Book I. Chap. 1. Note (b);) that is, into the foremention'd Bladders; fo that by blowing into the afpera Arteria, the Lungs will be a little rais'd, and the whole Belly blown up, fo as to be very turgid. Which doubtJefs is a Means to make their Bodies more or less buoyant, according as they take in more or lefs Air, to facilitate thereby, their Afcents, and Defcents: Like as it is in the Airbladders of Fishes, in the laft cited Place. Note (i).

(b) Such Birds as have long Legs, have alfo a long Neck; for that otherwife they could not commodiously gather up their Food, either on Land, or in the Water. But on the other Side, thofe which have long Necks, have not always long Legs, as in Swans

whofe Necks ferve them to reach to the Bottom of Rivers,, &c. Willughby's Ornithol. L. 1. C. Los pron

We have fufficient Inftances of this in Geefe, Ducks, &c, whofe Wings, (their Bodies being made for the Convenience of Swimming,) are plac'd out of the Center of Gravity, nearer the Head. But the extending the Neck and Head in Flight, caufeth a due Equipoife and Libration of the Body upon the Wings. Which is another excellent Ule of the

long

I might here take Notice of the Defect of the Diaphragm, fo neceffary in other Animals to Refpiration; and also of divers other Parts redundant, defective, or varying from other Animals. But it would be tedious to infift upon all; and therefore to the Examples already given, I would rather recommend a nice Infpection (k), of those curious Works of God, which would be manifeft Demonstrations of the admirable Contrivance and Oeconomy of the Bodies of those Creatures.

From the Fabrick therefore of their Bodies, I fhall pass to a Glance of one or two Things, relating to their State; and fo conclude this Genus of the animal World.

Jong Necks of thefe Birds, befides that of reaching and search. ing in the Waters for their Food.

But in the Heron, whofe Head and long Neck, (although tuck'd up in Flight,) over-balance the hinder Part of the Bo dy; the long Legs are extended in Flight, to counterpoife! the Body, as well as to fupply what is wanting in the Tail, from the Shortness of it.

(k) Steno thus concludes his Myology of the Eagle, Imper fecta hac Mufculorum defcriptio, non minùs arida eft Legenti bus, quàm Infpectantibus fuerit jucunda eorundem præparatio. Elegantiffima enim Mechanices artificia, creberrimè in illis obvia, verbis non nifi obfcurè exprimuntur, carnium autem du!! étu, tendinum colore, infertionum proportione, trochlearam diftributione oculis expofita omnem fuperant admirationem. Steno in Blaf. Anat. Animal. P. 2. c. 4.

СНАР. III.

Of the MIGRATION of Birds.

Oncerning the State of this Tribe of Animals, the firft Thing I fhall fpeak of, (by Realon God himself inftanceth in it,) fhall be their Migration, mention'd, Fer. viii. 7 Yea, the Stork in the Heaven knoweth her appointed Times,

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and

Book VII. and the Turtle, and the Crane, and the Swallow obferve the Time of their Coming; but my People, &c...

In which Act of Migration, there are two Things to me, exceedingly notable. One is what the Text fpeaks of, their knowing their proper Times for their Paffage, when to come (a), when to go; as alfo that fome fhould come when others go; and fome others go when these come. There is no doubt but the Temperature of the Air, as to Heat and Cold, and their natural Propenfity to breed their Young; may be great Incentives to thofe Creatures to change their Habitation: But yet it is a very odd Inftinct, that they should at all shift their Habitation: That fome certain Place is not to be found in all the terraqueous Globe, affording them convenient Food and Habitation all the Year, either in the colder Climes, for fuch as Delight in the colder Regions, or the hotter, for fuch Birds of Paffage as fly to us in Summer.

Alfo it is fomewhat ftrange, that thofe untaught, unthinking Creatures, fhould fo exactly know the beft and only proper Seafons to go and come. This gives us good Reafon to interpret the y appointed Times (b), in the Text, to be fuch Times as the Creator hath appointed those Animals, and hath accordingly, for this End, imprinted upon their Natures fuch an Inftinct, as exciteth and

(a) Curiofa res eft, fcire, quàm exacte hoc genus avium [Gruum] quotannis obfervet tempora fui reditus ad nos. Anno 1667. prima Grues comparuerunt in campeftribus Pifa 20 Feb. &c. F. Redi Exp. Nat. p. 1oo. ubi plura..

(6) From indixit, conftituit, feil. locum, vel tempus, ubi vel quando aliquid fieri debet. Buxt. in verb.

De voluntate fuâ certiorem reddidit. Con. Kircher concor dant. Pars. . Col. 1846. y Generaliter pro re aligua certa, atteftatâ, & definitâ accipitur. I. Pro tempore certo conftituto. 2. Deinde pro fefto fex Solennitate, que certo & ftato tempore celebratur. 3. Pro loco certo conftituto. Id. ibid. Col. 1847.

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