A text-book of comparative physiology for students and practitioners of comparative (veterinary) medicine (1890) (14760466651)

Identifier: textbookofcompar00mill (find matches)
Title: A text-book of comparative physiology for students and practitioners of comparative (veterinary) medicine
Year: 1890 (1890s)
Authors: Mills, Wesley, 1847-1915
Subjects: Physiology, Comparative
Publisher: New York, London, D. Appleton and company
Contributing Library: Columbia University Libraries
Digitizing Sponsor: Open Knowledge Commons



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Fig. 474.—Various positions in the trot (Colin) fleetest of horses, dogs, and other quadrupeds (Fig. 452). Itmay be seen that such an arrangement permits of a length-ened stride being taken with ease, tends to reduce concussion,and adds to beauty of form. To this must, in part at all events,be attributed the grace of form and fleetness of the race-horseand the greyhound, not to mention wild animals. A horse for heavy-draught purposes requires great muscularpower, which in turn implies a strongly developed osseous sys-tem; and in order that this may be attained some of thoseprinciples on which speed depends must be subordinated tothose involved in strength. As is well known, the cart-horseand race-horse, the mastiff and the greyhound, are opposites inbuild and capacity for speed. However, between these extremeforms there are many others of an intermediate character, asthe hunter, roadster, etc. When famous race-horses are studied,
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626 COMPARATIVE PHYSIOLOGY. while the form of the animal generally agrees with what wouldhave been expected on mechanical principles it is a fact thatsome of the fleetest horses that have ever run on the course havenot in all respects been built in conformity with them. Butit is to be remembered that a vital mechanism differs from allothers in that the whole consists of parts dependent not only asone portion of any machine is on the other, but that every partis energized and directed by a governing nervous system; thatevery cell is being in a sense constantly renewed, so that thecomparison between any ordinary mechanism and the body of aliving animal holds only to a limited extent. Moreover, apartfrom peculiarities in the muscles of animals, to which atten-tion has been drawn (page 205), it is well to bear in mind that notonly every animal, but every tissue has its own functional indi-viduality ; and to this especially (as exemplified in the most im-portant of all the tissues, the ner