[207] EXERCITATIO SEPTIMA.
De gallinae, aliarumque avium ventre.

7th exercise
The abdomen of the hen and of other birds

AB orificio igitur externo per vulvam, ad gallinae uterum sive matricem, pervenimus; in qua ovum perficitur, albumine cingitur, et testa contegitur: de cuius situ et positura antequam dicimus, nonnulla de ventris avium peculiari anatome huc afferenda, et praelibanda sunt. Observavi enim in pennatis, ventriculum, intestina, aliaque viscera, aliter in imo eorum ventre sita et constituta esse, quam in pedestri animalium genere.

Therefore, starting from the external orifice through the vulva, we reach the uterus of the hen or matrix in which the egg is perfected, is surrounded by the albumen and is covered by the shell. Before speaking of its location and disposition, at this point we have to report and mention some data related to the peculiar anatomy of the abdomen of the birds. In fact in the feathered animals I have seen that the stomach, the bowels and the other entrails are arranged and structured in the lowest part of their abdomen in a different way than in walking animals.

Aves fere omnes duplicem ventriculum nactae sunt; quorum alter ingluvies, alter ventriculus proprie dicitur. In priori, edulia ingesta reservantur et praeparantur; in posteriori, conficiuntur et in chylum transeunt: illum nostrates vocant the crop or craw; hunc, the gisard. In ingluvie aves grana integra devorata retinent; indeque, cum epota aqua madefacta, macerata, atque emollita, in ventriculum postea transmittunt; [208] ut ibidem molantur et comminuantur. Cuius rei gratia, pennata fere omnia arenulas, calculos, aliaque quaedam duriora deglutiunt, et in ventriculo una cum cibariis servant (dum interim in ingluvie nil tale reperitur); habentque hunc ventriculum ex duobus crassissimis et robustissimis musculis (in minoribus avibus carnosis aut ligamentosis) compactum; ut hoc modo, ceu duobus lapidibus molaribus, binis invicem cardinibus colligatis, molere cibaria et pinsere possint; vicemque dentium molarium, quibus carent, calculi suppleant. Hoc pacto alimenta conficiunt et chylificant; posteaque compressione facta (quemadmodum ex herbis aut fructibus contusis succum vel pulticulam exprimere solemus) pars mollior et liquidior sursum attollitur; eamque in principium intestinorum (quod in illis iuxta ingressum gulae, in ventriculi parte superiore collocatur) transferunt. Id ita fieri, in pluribus avium generibus apparet; in quorum ventriculis, si calculi, aliave duriora et aspera diutius permanserint, a continuo eorum motu adeo attrita et laevigata cernuntur, ut cibariorum attritioni inepta sint, ac propterea reiiciantur. Hinc aves, cum calculos eligunt, lingua probant; et, si nihil asperos senserint, reiiciunt. Hoc modo ferrum, argentum, et lapillos attritos et propemodum absumptos, in ventriculo struthionis inveni, atque etiam in Cassoware. Ideoque vulgo creditur, eos ferrum concoquere, et eodem nutriri.

Almost all the birds are endowed with two stomachs, one of which is called crop, the other one is rightly called stomach. In the first the ingested foods are kept and prepared, in the second they are digested and turned into chyle* - today called chyme*. Our countrymen call the first one crop or craw, the second one gisard - today gizzard. In the crop the birds preserve intact the grains they have eaten, and hence, wet with the drunk water, macerated and made soft, then they pass them in the stomach, so that  here they are grinded and minced. Thanks to this, almost all the feathered animals swallow sands, pebbles and some other harder things and they preserve them in the ventricle* - or gizzard or muscular stomach - together with the food (while on the contrary in the crop nothing of this type is found), and they have this ventricle which is made compact by two very thick and strong muscles (in the smaller birds they are of fleshy or membranous consistence), so that in this way they can crush and grind the foods as being two millstones connected to each other by two hinges, and the pebbles act as molar teeth which they - the birds - are lacking. In this way they mince the foods and turn them into chyme, and subsequently, after a compression has been done (like from grasses or from crushed fruits we usually squeeze a juice or a mash), the softer and more liquid part goes aloft, and they transfer it to the beginning of the bowels (which in them is located near the isthmus - passage between glandular and muscular stomach - in the upper part of the ventricle). It results that this happens in this way in almost all birds, in whose ventricles, if the pebbles or other rather hard and wrinkled things remained for a rather long time, because of their continuous movement they are to such a point worn-out and smoothed to be not suitable for the rubbing of the foods and therefore they are expelled. For this reason the birds, when choosing some pebbles, examine them with the tongue and if they felt that they are not wrinkled at all, they refuse them. So in the ventricle of an ostrich I have found iron, silver and smoothed almost consumed pebbles, and in a cassowary* too. And therefore the people believe that they digest the iron and feed on it.

Falconibus, aquilis, aliisque avibus ex praeda viventibus, si aurem prope admoveris dum ventriculus ieiunus est; manifestos intus strepitus, lapillorum illuc ingestorum, invicemque collisorum percipias. Neque enim falcones refrigerii causa (qui vulgaris accipitrariorum error est) lapillos devorant, sed ut eorum opera cibum comminuant: quemadmodum et aliae aves (quibus molendo victui ventriculus carnosus obtigit) in eundem finem, calculos, vel sabulum, vel quid aliud simile deglutiunt.

If while the stomach is fasting you will approach the ear to the hawks, to the eagles and to other birds living of preys, you will clearly hear at their inside some noises of pebbles which have been swallowed here and are bumping into each other. In fact neither the hawks eat the pebbles to refresh themselves (it is an usual error of the falconers), but to mince the food with their action. Likewise also the other birds (which have been blessed with a fleshy ventricle to grind the nourishment) swallow pebbles or sand or something similar with the same purpose.

[209] Avium igitur ventriculus, intra abdominis capacitatem, infra cor, pulmones, et iecur, situs est. Ingluvies autem extra corpus, ut plurimum, in infima colli parte, ad os jugale[1] haeret: in qua cibaria, ut dixi, emolliuntur solum et praeparantur; indeque pennata quaedam cibum ita maceratum pullis suis regurgitant, eosque nutriunt (quemadmodum quadrupedes foetus suos lacte alunt); ut videre est in omni columbaceo genere, atque etiam spermologis[2] illis, quos nos rooks nominamus. Quinetiam apes e floribus collectum mel, et in ventriculo digestum, domum redeuntes evomunt, et in propria alvearia recondunt: eodemque modo crabrones et vespae suos foetus nutriunt. Visa etiam est canis foemina cibos praemansos et semicoctos catulis suis nutricandis revomere. Ut minus mirum sit, foeminas pauperes victumque ostiatim quaerentes, prae lactis inopia, infantes suos cibis, prius in ore suo praeparatis et in pulpam redactis, alere.

Therefore the ventricle of the birds is located inside the capacity of the abdomen, below heart, lungs and liver. But the crop, mainly located out of the bodily mass in the lowest part of the neck, sticks to the jugal bone. In the crop, as I said, the foods only soften and prepare, and hence some birds regurgitate to their chicks the food so soaked and nourish them (likewise the quadrupeds nourish their newborns with the milk), as it is possible to see in all the species of pigeons, and also in those crows we call rooks - black crow Corvus frugilegus. Also the bees coming back to home regurgitate the honey picked up from the flowers and digested in the stomach, and they arrange it in their beehives; and in the same way the hornets and the wasps nourish their fetuses. Also a female of dog has been seen to vomit, to her little dogs to be fed, some foods already chewed and half digested. To be less marvelled: the poor women asking food from door to door, because of the shortage of milk nourish their children with foods previously prepared in their mouth and turned into a pulp.

Intestina in avibus, a parte ventriculi superiore, ut diximus, oriuntur; et secundum longitudinem sursum deorsumque (non transversim, ut in nobis) replicantur. Iisdemque statim sub corde, ad corporis praecincturam, ubi diaphragma (quo aves destituuntur) in quadrupedibus situm est, iecur amplum et bipartitum, utrinque (nam liene carent[3]) collocatum, hypochondria replet: infra iecur ventriculus positus est; cui subiacent intestinorum volumina, cum plurimis tenuibus membranis interiectis, aere repletis; quippe in has, ut diximus, asperae pulmonum arteriae foraminibus hiulcis aperiuntur. Renes (qui ampli in avibus visuntur) oblongi, et tanquam ex globulis carneis compositi, nullisque cavitatibus praediti, utrinque spinae, et arteriae, venaeque magnae descendenti adiacent; et in ampla atque oblonga ossis coxendicis cavitate sepulti iacent. Ex horum parte anteriore, secundum longitudinem, ureteres ad cloacam et podicem ipsum extenduntur; ut deorsum excrementum [210] illuc a renibus deferant. Est autem in avibus huius seri exigua quantitas, quod illae parum bibant, et earum nonnullae, nimirum aquilae, nihil omnino. Nec separatim, ut in aliis animalibus, urina profluit; sed, ut diximus, in communem cloacam, alvi quoque faecibus dicatam, ex ureteribus destillat; ut earum etiam hoc pacto exitum facilitet. Differt hoc lotium in  avibus, atque in aliis animalibus: nam, cum urinae partes duae sint, serosior una et liquida; crassior autem altera, quae in sanis hypostasis[4] nominatur, et in urina iam refrigerata subsidit; aves (contra quam vivipara animalia) maiorem huius copiam obtinent; eaque, ab altera, colore albo sive argenteo distinguitur; et non modo in cloaca reperitur (ubi abundat) alvique faeces circumlinit, sed etiam in toto ureterum ductu; qui a renum tunicis, hac ipsa albedine discernuntur. Nec solum in avibus crassior haec materia a renibus descendens conspicitur; sed in serpentibus etiam aliisque oviparis; praesertim iis, quorum ovum duriore cortice obducitur. Maior quoque huius, quam serosae et tenuioris partis, copia: estque consistentiae, inter crassam urinam et stercoraceum excrementum, mediae; adeo ut ureteres pertransiens, lac coagulatum sive leviter densatum referat; forasque eiectum, cito facileque in crustam friabilem concrescat.

As I said, in the birds the bowels originate from the upper part of the ventricle and they bend upward and downward according to the length (not transversally, as in us). And still in them, immediately under the heart, near the  girdle, where in the quadrupeds the diaphragm is placed (in which the birds are lacking), a liver big and divided into two parts, arranged on both sides (in fact they don't have the spleen), fills the hypochondria: the ventricle is placed below the liver, under which the volutes of the bowels are placed together with a lot of thin interposed membranes full of air - the air sacs. In fact, as I said, in them are opening some rough channels of the lungs with some chapped holes. The kidneys (which in the birds appear wide) are lengthened and, constituted as by globules of flesh and not endowed with cavity, they are adjacent to the two sides of the backbone and to the great artery and the great vein that go down, and they lie buried in a great and long cavity of the bone of the hip. From their front the ureters, longitudinally arranged, extend until cloaca and vent, so to transfer downward in them the excretion of the kidneys. In reality in the birds the quantity of this serous liquid is little, since they drink a little, and some of them, that is, the eagles, don't drink at all. Neither the urine comes out in a separate way as in the other animals, but, as I said, it drops from the ureters in the common cloaca also devoted to the faeces of the intestine, so to also facilitate their discharge in this way. This urine is different in the birds, and also in the other animals: in fact, since the parts composing the urine are two, one rather serous and liquid, the other rather dense that in healthy subjects is called sediment and goes downward in the already cooled urine. The birds (unlike the viviparous animals) have a greater abundance of the latter, which differs from the other one for the white or silver colour, and it is not found only in the cloaca (where it abounds) and smears on the faeces of the intestine, but also in the whole duct of the ureters, which differ from the tunics of the kidneys for this same whiteness. This rather dense matter that goes down from the kidneys is not only seen in the birds, but also in the snakes and other oviparous animals, especially in those whose egg is covered by a rather hard shell. The quantity of this liquid is greater in comparison with the serous and little dense component, and has a consistence in middle between a dense urine and a dung excrement, so that while passing through the ureters it resembles a coagulated or slightly thickened milk, and after having been issued outside it quickly and easily condenses into a friable crust.