Researches upon the anatomy and physiology of respiration in the Chelonia / by S. Weir Mitchell and George R. Morehouse.

  • Mitchell, S. Weir (Silas Weir), 1829-1914.
Date:
[1863]
Catalogue details

Licence: Public Domain Mark

Credit: Researches upon the anatomy and physiology of respiration in the Chelonia / by S. Weir Mitchell and George R. Morehouse. 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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    CHATTER, II. The preceding chapter has boon altogether taken up with anatomical descriptions of the respiratory organs and their appendages. So much that was now w;is met with during our dissections, that it was thought better to separate the description of the anatomy from the physiological statements. We have thus tin; physiology of the respiratory organs still to describe, and this can now be done without repeating any more of the anatomioal detail than is necessary to enable the reader to comprehend the actions of the organs concerned. The history of the theories entertained as to the nature of the respiratory motions in turtles, appears to us one of the most extraordinary in the records of science. Totally misunderstood by the earlier naturalists and biologists, or con- founded as to type with the respiration of Batrachians, this function in turtles was first rightly comprehended, at least to some extent, by 11. Townson in the latter part of the last century, liow far he went, and how far he was correct, we shall more fully point out in another place. The authority of more eminent naturalists, and an obstinate disposition to associate the turtle with the frog, and to insist on similarity as to the execution of their functions, gradually drew attention from Townson's statement, and more modern authors have paid it no deference what- ever ; yet, as we shall distinctly show, all the later writers are utterly wrong, and his opinions as to the facts in question arc thus far the only ones which seem to be correct. In reading his very ingenious essay, which we have elsewhere quoted at length, p. 2, it is hard to sec how the statements and evidence could have failed of more respectful and permanent attention. A complete review of the theories enter- tained in regard to the respiratory function in Chelonian reptiles, will more fully illustrate the above remarks. As early as 1719, Malpighi1 described the respiration of turtles as similar to that of frogs. Both alike wore supposed to distend the lungs by swallowing air, so that, in place of air being drawn into the lung-sacs, it was forced into them by the movements of parts above the trachea; but while in the frog this was effected plainly through the aid of the bellows-like mouth, in the turtles their vast hyoid apparatus was by some supposed to constitute a forcing pump of similar purpose and nature. The authors of Malpighi's era shared these opinions, and with the one notable; exception above mentioned, they have stood almost uncontradicted up to the date of a paper by one of the authors of the present essay. 1 Adversaria Anatomica, t. v Animadv, 29.