File:Evolution and disease (1890) (14577084730).jpg

Identifier: evolutiondisease00blanuoft (find matches)
Title: Evolution and disease
Year: 1890 (1890s)
Authors: Bland-Sutton, John, Sir, 1855-1936
Subjects: Diseases -- Causes and theories of causation Medical genetics Abnormalities, Human Animals -- Abnormalities
Publisher: New York, W. Scott
Contributing Library: Kelly - University of Toronto
Digitizing Sponsor: MSN

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oright to such a title, and it will be useful for us toconsider the various forms of true tails and the appen-dages which may be mistaken for them. We may, with Virchow, dividetails into two classes, true andfalse. True tails are of twovarieties : the most perfect tailsare composed of bony segmentsdirectly continuous with thevertebral column, as in the caseof monkeys, horses, dogs, cats,lions, &c. The less perfectvariety is like that of the pig,soft and flexible. That manhas descended from ancestorswhich possessed tails there canbe little reasonable doubt, andthat children are occasionallyborn with one and even twoextra bony segments to thecoccyx, as mans rudimentarytail is termed, is undoubted. Ihave on several occasions seen five rudimentary vertebraein a childs coccyx. It must also be remembered that this portion of thevertebral column may be more prominent than usual andproject like a tail, yet on dissection contain but thenormal number of bony elements ; whilst in other cases
Text Appearing After Image:
Fig. 27.—a Faun, to showthe goat-like tail. DISUSE AND ITS EFFECTS. 55 the number may amount to five, and no abnormal pro-jection be observable. Thus far a well-developed tailin an adult human subject containing bony elementscontinuing the vertebral series has yet to be detected.In the new-born child, soft tails about an inch in lengthhave been observed : these contained cartilaginous tissueand resembled the flexible tail of pigs.

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