The study of medicine: with a physiological system of nosology (Volume 3).

  • Good, John Mason, 1764-1827.
Date:
1825
Catalogue details

Licence: Public Domain Mark

Credit: The study of medicine: with a physiological system of nosology (Volume 3). 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.)

    17/440
    The difference in the external senses of the different orders and kinds of animals consist in their number and degree of energy. All the classes of vertebral animals possess the same number of senses as man. Sight is wanting in zoophytes, in various kinds of molluscous, and articulated worms, and in the larves of several species of insects. Hearing does not exist, or at least has not been traced to exist, in many molluscous worms and several insects in a perfect state. Taste and smell, like the general and simple sense of touch, seem seldom to be wanting in any animal. The local sense of touch, however, or that which is of a more elaborate character and capable of being exercised in a higher de- gree, appears to be confined to the three classes of mammals, birds, and insects; and even in the last two it is by no means common to all them, and less so among insects than among birds. In apes and macaucoes, constituting the quadrumana of Blumen- bach. it resides partly in the tongue, and tips of the fingers as in man, but equally, and in some species even in a superior degree, in their toes. In the raccoon (ursus lotor) it exists chiefly in the under surface of the front toes. In the horse, and cattle orders, it is sup- posed by most naturalists to exist conjointly in the tongue and snout, and in the pig and mole to be confined to the snout alone ; this how- ever is uncertain ; as it is also, though there seems to be more rea- son for such a belief, that in the elephant it is seated in the pro- boscis. Some physiologists have supposed the bristly hairs of the tiger, lion, and cat, to be an organ of the same kind; but there seems little ground for such an opinion. In the opossum (and es- pecially the Cayenne opossum) it exists very visibly in the tail; and M. Cuvier suspects that it has a similar existence in all the prehensil-tailed mammals. Blumenbach supposes the same sense to have a place in the same organ in the platypus or ornithorhyncus as he calls it, that most extraordinary duck-billed quadruped which has lately been disco- vered in Australasia, and, by its intermixture of organs, confounds the different classes of animals, and sets all natural arrangement at defiance. The local organ of touch or feeling in ducks and geese and some other genera of birds, appears to be situated in the integument which covers the extremity of the mandibles, and especially the upper mandible, with which apparatus they are well known to feel for their food in the midst of mud in which they can neither see nor perhaps smell it. We do not know that amphibials, fishes, or worms, possess any thing like a local sense of touch; it has been suspected in some of these and especially in the arms of the cuttle fish, and in the ten- tacles of worms that possess this organ, but at present it is sus- picion and nothing more. In the insect tribes, we have much reason for believing such a sense to reside in the antennas or in the tentacles; whence the for- mer of these are denominated by the German n&tura\h\.s fiihlhornc*