Outlines for a Museum of Anatomy / prepared for the Bureau of Education.

  • Robert Wilson Shufeldt
Date:
1885
Catalogue details

Licence: Public Domain Mark

Credit: Outlines for a Museum of Anatomy / prepared for the Bureau of Education. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    making up as they do the v^ast majority of living birds, possess well, developed wings and a keeled sternum. Extinct ancestors of birds are also awarded two orders, the Sauriirw, which contains the Archaiop- teri/x, and the Odontornithes^ already mentioned, which contains the toothed birds discovered by Marsh in the cretaceous beds of Kansas, As with birds, so it is with mammals; in all parts of the world the fossil remains of their progenitors are to be found. New forms come to light every day, some simple, some wonderfully complex, but all easily accounted for when submitted to the doctrine of descent. One of the best examples of this is the series of animal remains from sev- eral geological horizons, showing the origin of the horse. This illus- tration is familiar to all who have read Professor Huxley’s description of it, or indeed auy good modern work upon geology.^ Speaking of the classification of living Mammalia, a very eminent zoologist says: A perfect arraugemeut of auy group of animals cau only be attained siinultaueoiisly ■with a perfect knowledge of their structure and life history. We are still so far from this that auy classification now advanced must he regarded as provisional, and merely representing our present state of knowledge. Moreover, as naturalists will estimate dififerently the importance to he attached to ditt'erent structural modifications as in- dicative of affinity, it must be long before there will be any general agreement upon this subject.» • The classification most generally adopted is the one originally pro- posed by De Blainville, which divides all living Mammalia into three groups. These three groups are (1) Monodelphia, (2) Didelphia, and (3) Ornithodblphia. The last subclass mentioned, the Orni- thodelphia, contains but the single order of the Moiwtremes, or the Mouotremata. This order includes but two living forms, the well- known duck-bill {Ornitliorhynchus) and the spiny ant-eater {Echidna hystrix). These very interesting animals are confined to the Australian continent, the off-lying island of Tasmania, and two forms of Echidna in New Guinea. Morphologically they are distinguished by the follow- ing characters: there is a large cloaca (vent), common to the rectum and the urinary and genital organs, as seen in birds; and in com- mon with these and also with the Amphibia we find the large beak- shaped processes of the shoulder-blades articulating with the breast- bone. A T-shaped interclavicle also exists, differentiating them from all other mammals. They have no true teeth, but horny bills, like bii ds, and the very imperfect young, when they are born, have a nib in the end of this bill, as we see in chickens and other lowls. In- deed, nearly all their characters, forming too long a list to mention in full here, link them with reptiles, birds, and the Amphibia, or reallj ‘ See .Joseph Le Conte, Elements of Geology, p. 53fi. New York, 168.?. Also Leehiret on Evolution, by Thomas II. Huxley. Published in the Humboldt Library, No. -Ifii vol. ii. New York, September, 1882. 2 William,Henry Flower, F.R.S., etc. An Introduction to the Osteology of the Mars- ntalin, page 1. London, 1876.
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