Observations on certain parts of the animal oeconomy : inclusive of several papers from the Philosophical transactions, etc. / by John Hunter ... ; with notes by Richard Owen.
- John Hunter
- Date:
- 1840
Licence: Public Domain Mark
Credit: Observations on certain parts of the animal oeconomy : inclusive of several papers from the Philosophical transactions, etc. / by John Hunter ... ; with notes by Richard Owen. Source: Wellcome Collection.
Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)
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![in both seasons. Nor will the powers of the stomach be found always equal in the same class. Sleeping animals of the quadruped kind, as hedgehogs, do not digest in the winter, but in the summer only ; therefore the conclusions to be drawn from experiments made respecting the digestive powers in the one, are not at all applicable to those made in the other season. Spallanzani observed that the snake digested food faster in June, when the heat was at 82° and 83°, than in April, when it was only 60°; from whence he concludes, that heat assists digestion ; but this heat is not the immediate, but the remote cause of the increased power; heat having produced in the animal greater necessity for nourishment, and of course- greater powers, gastric juice was secreted faster or in greater quantity. As a proof that heat docs not act as an immediate, but only as a remote cause in assisting digestion, I shall mention the effect it pro- duced upon a hedgehog, the subject of Mr. Jenner's third experi- ment on the heat of that animal, related in another part of this work. The hedgehog, while the heat of the stomach was at 30°, had neither desire for food, nor power of digesting it; but when in- creased by inflammation in the abdomen to 93°, the animal seized a toad which happened to be in the room, and, upon being offered some bread and milk, it immediately ate it. The heat roused up the actions of the animal ceconomy ; and the parts being unable to carry on these actions without being supplied with nourishment, the stomach was stimulated to digest, to afford them that supply. Spallanzani also mentions the slowness of digestion in serpents, and quotes Bomare, who gives an account of a serpent at Martinico, in whose stomach a chicken had remained for three months without being completely digested, the feathers still adhering to the skin.* The truth of this fact I should very much doubt, especially in so warm a climate as that of Martinico, where I must suppose the digestive powers to be constantly required; unless there is in Martinico, as in colder climates, a torpid season,f where the act of digestion is not necessary ; but in that case the serpent would not have swallowed the chicken. At Belleisle, in the beginning of the winter 1761-2, I conveyed worms and pieces of meat dow n the throats of lizards when they were going into winter quarters, keeping them afterwards in a cool place. On opening them at different periods I always,found the substances which 1 had introduced entire, and without any altera- tion: sometimes they were in the stomach ; at other times they had * Bomare, Diet. d'Histoirc Nat. f [This conjecture is true; the dry season in some tropical climes is that during which reptiles and inserts retire to their hiding-places and become torpid ; they are awakened and called into activity by the showers of the rainy season. The tenrec, a mammiferous animal of Madagascar and the Mauritius, re- sembling the hedgehog, also sleeps in a state of lethargy from April to Novem- ber, when the mean temperature exceeds our summer heat.]](https://iiif.wellcomecollection.org/image/b21131545_0084.jp2/full/800%2C/0/default.jpg)
