A systeme of anatomy, treating of the body of man, beasts, birds, fish, insects, and plants illustrated with many schemes, consisting of variety of elegant figures, drawn from the life, and engraven in seventy four folio copper-plates. And after every part of man's body hath been anatomically described, its diseases, cases, and cures are concisely exhibited. The first volume containing the parts of the lowest apartiments of the body of man and other animals, etc. / by Samuel Collins ...

CHAP. VI. Of the Midriff of Fish.

THe Midriff of Cetaceous Fish differeth very much from that of other, as it is an Engine of Motion, consisting of Carnous and Tendinous Fibres, enlarging the circumference of the Thorax in dimensions, by bring∣ing its Concave Surface to a Plain, to entertain the Lungs Dilated with the Elastick Particles of Air, puffing up their substance.

The Midriff of ordinary Fish is not capable of motion, * 1.1 as being a Carti∣laginous substance or Membranous Contexture, not interspersed with Fleshy and Tendinous Fibres, the fine Machines of Motion, whereby the Dia∣phragm of most Fish serveth only as an Intersepiment to part the Gills and Heart from the Viscera reposed in the lowest apartiment of the Body.

But the Midriff of a Porpess is made up of an upper and lower Membrane, * 1.2 interlined every way with a thick Muscular Expansion, and differeth from the Diaphragm of Quadrupeds, because it is destitute of an Aponeur••sis in the middle, where it is also Fleshy, as well as in the circumference, which I clearly saw in a Porpess opened, wherein I separated the two Membranes from the inward Fleshy substance; passing every where between the two Coats.

The Diaphragm of this Animal is fastned one way to the Vertebres of the Back, and on the other to the Terminations of the Ribs and Sternon, * 1.3 and on each side to the Arches of the lower Ribs, by the interposition of various Fibres.

The Muscular Expansion seated in the middle of two Membranous Inte∣guments, is made up for the most part of right Fibres, * 1.4 (running from the Center to the Circumference) and some few seem to be oblique, and others circular about the Perforation made by the Gulet:

The Midriff of a Porpess is not only beset with many Fleshy Fibres but Ten∣dinous too; some being very large do pass down the Spine, and others creep over the Psoas, and many other smaller Tendinous Fibres are intermingled with the Fleshy, which may be discerned on each side of the Diaphragm.

The Fleshy and Tendinous Compage of this Orbicular Muscle is invested above and below with a fine Covering.

The outward or rather upper Tunicle, is very thin, * 1.5 and made up of many minute Membranous Filaments rarely framed in variety of Positions.

The lower Integument is a thicker Coat, made up of many Nervous Fi∣brils, finely spun, closely struck, and curiously interwoven.

The use of the Midriff in this Animal, * 1.6 is the same with that of Man and Quadrupeds, to be a machine of Motion, whereby it bringeth it self from an Arch toward a Plain, to render the Cavity of the Thorax more long to give way to the expanded Lungs in Inspiration.

The Midriff of most if not all Fish, except those of a Cetaceous kind, * 1.7 have a Cartilaginous (which is rare) or Membranous substance not inter∣lined with a Muscular Expansion, nor beset with Fleshy and Tendinous Fi∣bres, as they are not Machines of ordinary Motion, but serve only as a party-wall, severing the middle from the lowest apartiment.

A Fire-flaire, * 1.8 or Sting-Ray, is so called from a Bone composed of many Processes or Teeth, (received into many Cavities near the Spine) with which Nature hath armed this Fish against outward assaults.

This Fish hath a Cartilaginous Diaphragm, having a Concave Surface to∣ward the lower Venter, and Convex toward the Mouth and Heart.

The Midriff of a Dog-fish is a Membranous Compage, * 1.9 composed of two Coats, and is endued with a Concave Surface toward the Mouth and middle Apartiment, and a Convex toward the lowest Venter.

Notes

• * 1.1

  The Midriff of ordinary Fish is immove∣able.
• * 1.2

  The Compage of the Midriff of a Porpess.
• * 1.3

  The connexi∣on of the Dia∣phragm in a Porpess.
• * 1.4

  The Fibres of the Dia∣phragm of a Porpess.
• * 1.5

  The upper Tunicle of the Midriff. The lower Coat of the Diaphragm.
• * 1.6

  The use of the Midriff in this Animal.
• * 1.7

  The Midriff in Fish is some∣times Carti∣leginous, and for the most part Membra∣nous.
• * 1.8

  A Fireflaire hath a Carti∣laginous Dia∣phragm.
• * 1.9

  The Midriff of a Dogfish.