Abstract
American Journal of Science and Arts, April.—An opening obituary notice of the distinguished botanist, Dr. Jacob Bigelow, who died in January, aged 92, is here followed by a note in which Prof. Marsh traces the connection between the two widely divergent forms of vertebræ of the toothed birds Ichthyornis and Hesperornis. In the former the articulation of the centrum is cup-shaped; in the latter the ends of tne centrum are saddle-shaped, as m ordinary birds. The third cervical vertebra of Ichthyornis, however, has a transition form, affording a ready solution of the development of the modern avian vertebra from the fish-like. The order of development of vertebræ seems this: Biconcave vertebræ (fishes and amphibians), plane vertebræ (mammals), cup and-ball vertebræ (reptiles), saddle vertebræ (birds).—The double stars discovered by Mr. Alvan G. Clark, which (except Sirius) have not been brought to the attention of astronomers generally, are the subject of a paper by Mr. Burnham.—Interesting details are furnished by Prof. Church of underground temperatures in the Comstock lode in Nevada, where are, apparently, the hottest mines in the world. (The rock in the lower levels seems to have a pretty uniform temperature of 130° F.)—Prof. Lesquereux contributes a review of Count Saporta's valuable work on the plants of the world before man, taking occasion to compare the essential characters of certain tertiary groups of the North American continent, in order to determine some points still under discussion as to their age.—Mr. Palsinger indicates a method of estimating the thickness of Young's reversing layer; and among other subjects dealt with are, the lower jaw of Loxolophodon and the presence of chlorine in scapolites.
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Scientific Serials . Nature 20, 22 (1879). https://doi.org/10.1038/020022b0
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DOI: https://doi.org/10.1038/020022b0