The book of nature; or, the history of insects: reduced to distinct classes, confirmed by particular instances, displayed in the anatomical analysis of many species, and illustrated with copper-plates ... / by John Swammerdam, M.D. With the life of the author, by Herman Boerhaave, M.D. Translated from the Dutch and Latin original edition by Thomas Flloyd.
- Jan Swammerdam
- Date:
- 1758
Licence: Public Domain Mark
Credit: The book of nature; or, the history of insects: reduced to distinct classes, confirmed by particular instances, displayed in the anatomical analysis of many species, and illustrated with copper-plates ... / by John Swammerdam, M.D. With the life of the author, by Herman Boerhaave, M.D. Translated from the Dutch and Latin original edition by Thomas Flloyd. Source: Wellcome Collection.
91/614 page 53
![thoroughly of thofe parts, which were firft ob¬ vious to me. Neither need I be uneafy, if I have delineated one part fomewhat larger, and the other fomewhat lefsj the microfcope not admitting of greater accuracy: and indeed this avails nothing in our attempts to inculcate a knowledge of the fubje<ft, unlefs fome particular points may be more diftinctly underftood, if on that occafion, the parts are exhibited a little larger than the life. The beft manner of differing the Snail is the/hell Tab. IV. fig. u.being pulled off, to begin at the verge of the body, fig. Im e . which alfo fhould be cut off from the left fide’ with a fine pair of fciffors 3 in the doing this] taking care not to pierce the apertures g, fituated on its right/; thefe ftill remaining unhurt, the 1S be feParated from the body, which vihbly adheres to it below 3 for otherwife, unlefs thefe apertures be carefully avoided, the outlet of the inteftines, and the paffage of the alkaline bag, will be equally injured. In this management, what firft meets the eye, is the skin of the fubjacent body, which is concealed by the upper and under part of the verge, or a membranaceous fubftance, as with a covering, being much more delicate about that place, and of a whitifh or palifh colour, and compofed of oblong mufcular fibres. If you have nicely feparated this part of the inter¬ nal skin, you will fee the tranfverfe mufcles lying under it 3. which, though not altogether colourlefs, are in fome degree tranfparent ; and on both fides, in the foft or bending part of the belly, there will be oblerved certain mufcles refembling a faw, which ftretch their tendons above the peritoneum 3 but the fmall mufcle, running tranfverly, is fituated above the perito¬ neum, under which it lies. All thefe mufcles ferve to prefs the body inwards, and to move forwards the contents of the inteftines, and of the fpermatic veffels. . ^ut after verge, together with its membranaceous parts, be drawn backwards over the bending of the body, and then cut off from the place where it adheres, then imme¬ diately appear the veins. Tab. V. fig. iV. a, which run beneath toward the verge b, and the heait c, with its auricle d, and the vena cava juft dawning out of it 3 together with the various cavities, in which the air is moved, and fome other fmall parts befide, fuch as the alkaline bag e, and its dud: lying next to the inteftine, the inteftinum return ƒ itfelf, the liver, and certain parts belonging to the fpermatic veffels. Some of thefe I fhall now defcribe in their order, and of the others afterwards in their place. Firft, of the heart. The heart is fituate in the middle of the Snail’s body, near the extremity of the arch of the verge, which furrounds the whole bo¬ dy j and at that place, a little to the left, in the bending of the body, by reafon of the thinnefs of the inteftine membranes, which are perfedly tranfparent, Tab. IV. fig. 1. /, Jt xs dilcerned moving. It is included in an ex- 53 tremeiy thin bag or pericardium, in whofe cavity there is ample abundance of watery moilture, as clear as the pureft chryftal. The pericardium being diffeded, immediately ap¬ pears the beating heart, Tab. V. fig. iv. c, with its auricle d; which, being of a mem¬ branaceous and exceeding delicate texture, is feen to be interwove within, with divers as well fleftiy as membranaceous fibres, in the fame manner as is feen in the auricles of the heart of a man, and other animals. The heart itfelf is of a flefhy fubftance, and of a pale reddifh colour, exhibiting a mufcle, which or the fpace of a day will continue waftin^ away into water, and yet not be cleared from all its blood. The external fuperficies of the heart is ftnooth, and it is fhaped like a pear; but the internal parts are uneven, with feveral fleftiy columns, hairs, and fibres, much the fame as we obferve in the hearts of men and brutes: . hence it is that the heart may be eafily diftinguiftied by the many finufes and angles in it, and it is very fibrous. At its entrance,, near the auricle, there adhere two little femi-lunar valves c, which ferve to hinder the blood from returning into the auricle. But as there is only one auricle to the heart, fo is it only found in one cavity 3 and agreea¬ bly to this, there are alfo found two kinds of veffels there, namely, the veins and arteries. The veins, above the auricle d of the heart, are confpicuous without much pains, and in particular the vena cava may be obvioufly feen; out of which others, juft fpringing forth, arc interwoven amongft one another after a fur- piifing manner, and form an elegant kind of net-work. The arteries are not difcovered without greater difficulty, nor can they ever be feen, but at the firft opening of the body. The beginning of the aorta, or great artery, is about that place without the belly, where the heart is united to the calcarious bag ^3 and the great artery derives its origin from the cone, or more acute extremity of the heart, and is a liftle dilated, at its very beginning, as is common in fifties 3 immediately from this pait it difperfes its ramifications every way, both through the internal parts of the body, and outwardly among the membranes, equally backward to the fpire, and forward; firft, in¬ deed, refpefting thofe parts it borders upon, namely, the calcarious bag e} the inteftines, the liver, the ftomach, and thé fpermatick veffels 3 then immediately proceeding to the coat in¬ verting the liver, and then to the mufcles, nerves, and little glands of the skin. I have delineated h fome of the more remarkable ra¬ mifications, only with their divifions, and have marked the reft of its body, and its fpiral fhape, with points tiiiy that the fituation of thefe parts might thence be underftood. The blood contained in the heart, and its arteiies, appears of a whitifti colour, inclining fomething to blue 3 and hence it differs very much from that of men and brutes 3 for the blood](https://iiif.wellcomecollection.org/image/b30448542_0091.jp2/full/800%2C/0/default.jpg)
