Observations on certain parts of the animal oeconomy / by John Hunter.
- John Hunter
- Date:
- MDCCXCII [1792]
Licence: Public Domain Mark
Credit: Observations on certain parts of the animal oeconomy / by John Hunter. Source: Wellcome Collection.
Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.
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![Having endeavoured to iliow that the funcflion of thefe veficulce has hitherto been mifunderfhood, the following obfervations will tend to prove that they are fubfervient to generation, though their particular ufe is not yet difcovered; and, for the better underflanding this part of the fubjecS, I fhall premife the follovv^ing fafts. Animals have their natural feelings raifed or increafed, according to the perfedlion of the parts conneded with fuch feelings. And the difpo- fition for action is alfo in proportion to the flate of the parts and the excitement of fuch feelings. But that thefe feelings may be duly excited, it is necelTary that the animal and the parts fliould be healthy, in good condition, and in a certain degree of warmth fuitable to that clafs to which the animal belongs. In the greateft part of the globe there is a difference in the warmth of the fame diflrict at different periods, confti- tuting the feafons ; and the cold in fome of them is fo confiderable, as to prevent thofe feelings or difpolitions in animals from taking place, and to render them, for the time, unfit for the purpofes of generation*. This is owing to the tefticles becoming at this feafon fmall, and being therefore unfit to give fuch difpofitions, as is the cafe in very young animals. This faft is very obvious in birds, of which the fparrow may be produced as a proof. For if a cock-fparrow is killed in the winter, before the days have begun to lengthen, the tefticle will be found very fmallt^ but if that organ is examined at different times in other fparrows, as the warmth of the weather increafes, and if this examination is continued to the breed- ing feafon, the difference in the fize of the tefticle will be very ffriking;];. This circumftance is not peculiar to birds, but is common, as far as I yet know, to all animals which have their feafons of copulation. In the buck we find the tefticles are reduced to a very fmall fize in the winter; and in the land-moufe, mole, &c. this diminution is ftill more remarkable. * It is not required that the feafon for the copulation of different animals fhould be equally warm; for the frog copulates in very cold weather; while the fnake and lizard, which are alfo cold, fleeping animals, do not copulate till the feafon is warm. t Vide plate VII, fig. i. J Vide plate VII, fig. 5, G](https://iiif.wellcomecollection.org/image/b21172924_0063.jp2/full/800%2C/0/default.jpg)
