252 



NATURE 



[October 21, 1920 



the latter in order to cause stimulation; thus the 

 position of the long axis of the rhabdome results in 

 a localisation of photic stimulation. Light entering 

 the pigment-cup from any given direction illuminates 

 the rhabdomes in a definite area, and a large propor- 

 tion of these have their long axes directed parallel 

 to the stimulating rays of light. 



We have received from Prof. H. F. Osborn reprints 

 of some interesting brief notes on vertebrate fossils 

 in the American Museum of Natural History, New 

 York. A good drawing is published of a newly 

 mounted skeleton of Moropus, the strange odd-toed 

 hoofed mammal from the Miocene of Nebraska, in 

 which the large hoofs are sharply pointed and deeply 

 cleft as in some edentates (Proc. Nat. Acad. Sci., 

 vol. v., pp. 250-52, 1919). Prof. Osborn concludes 

 that this must have been a forest animal, and that 

 the peculiar feet were used, not for digging, "but 

 largely for the pulling down of the branches of trees." 

 A drawing of a restored and mounted skeleton of a 

 long-jawed mastodon (Megabelodon) from the Pliocene 

 of Texas shows well the comparatively short limbs of 

 the earlier elephant-like mammals (Proc. Nat. Acad. 

 Sci., vol. v., pp. 265-66, 1919). Beginning apparently 

 in northern Africa, these long-jawed mastodons 

 reached Europe in Lower Miocene times, and 

 appeared in America (Texas) in the Upper Miocene, 

 attaining a gigantic size in the Middle Pliocene. The 

 monograph of the Titanotheres is progressing, and 

 Prof. Osborn describes some new fragments of jaws 

 from the Eocene of Colorado (Bull. Amer. Mus. 

 Nat, Hist., vol. xli., art. xv., 19 19). The Jurassic 

 Dinosaurs are also being actively studied, and some 

 valuable notes on the original specimen of the gigantic 

 sauropod, Camarasaurus, from Colorado, are pub- 

 lished by Prof. Osborn and Mr. C. C. Mook (Proc. 

 .\mer. Philos. Soc, vol. Iviii., pp. 386-96, 1919). The 

 authors agree with Dr. W. J. Holland that the axis 

 of the skull in the sauropods inclines downwards 

 from the vertebral axis as an adaptation for brows- 

 ing, and they give some striking restored sketches of 

 the head of Camarasaurus as they think it appeared 

 in life. 



The Memoirs of the Geological Survey of India 

 (vol. xlvii., part i) contain an extremely interesting 

 account of the mines and mineral resources of Yunnan 

 by Mr. J. Coggin Brown. Yunnan is the most south- 

 westerly of the provinces of China, and is of import- 

 ance from the British point of view because it forms 

 the eastern boundary of Burma and .Assam ; it has 

 been but little visited by Europeans, and Mr. Coggin 

 Brown's explorations thus afford authentic informa- 

 tion upon an extensive area which has hitherto been 

 most imperfectly studied. The more important 

 mineral products which he has described comprise 

 coal, iron, copper, lead, silver, zinc, tin, arsenic, 

 gold and salt. In addition to Tertiary lignite, coal 

 of Mesozoic, Triassic and Carboniferous age is 

 known, and the author is of the opinion that the 

 province contains considerable quantities of coal, 

 some of which, at any rate, is of good quality. He 

 does not think there is much probability that coal 

 can be exported in competition with other coalfields 

 NO. 2660, VOL. 106J 



of the Far East, but holds that it will find its chief 

 demand in supplying the local railways and local 

 domestic and metallurgical requirements. Iron ores 

 occur in many places, and the production of cast- 

 iron, castings, wrought iron and steel is sufficient 

 for all local requirements, which are, of course, by 

 no means extensive. The native methods of iron- 

 smelting are well described, and it is interesting to 

 find that the Chinese have developed charcoal blast- 

 furnaces 25 ft. in height and 7 ft. across the boshes. 

 The author does not think that there is much room in 

 Yunnan for the development of iron-smelting upon 

 modern European lines, but that the native smelters 

 will gradually learn to improve their own methods. 

 It is stated that copper has been smelted in Yunnan 

 for at least a thousand years, but although copper 

 ores are widely distributed the industry appears to 

 be a declining one. The same seems to be true of 

 lead and silver, but the production of tin, on the other 

 hand, is in a flourishing condition. 



Some interesting facts showing the limits of the 

 continental United States which have been compiled 

 by the United States Geological Survey are published 

 in Science of September 24. The gross area of the 

 United States is 3,026,789 square miles, of which 

 2,973,774 square miles are land and the remainder, 

 53,015 square miles, water; this is exclusive of the 

 area occupied by the Great Lakes and that within 

 the three-mile limit on the Atlantic and Pacific sea- 

 boards and in the Gulf of Mexico. The most 

 southerly point of the mainland is Cape Sable, 

 Florida, which is in latitude 25° 7' N. and longi- 

 tude 81° 5' W. ; this point is really forty-nine miles 

 further south than the southernmost point of Texas, 

 which often appears in maps to be the most southerly 

 part of the land territory of the United States. The 

 most easterly point is West Quoddy Head, near East- 

 port, Maine, in longitude 66° 57' W. and latitude 

 44° 49' N. ; and the most westerly Cape Alva, Washing- 

 ton State, in longitude 124° 45' W. and latitude 

 48° 10' N. A small detached land area of northern 

 Minnesota provides the most northerly point, in 

 longitude 95° 9' W. and latitude 49° 23' N. 

 The distance from the most southerly point of 

 Texas due north to the forty-ninth parallel, the 

 boundary line between the United States and 

 Canada, is 1598 miles. From West Quoddy Head 

 due west to the Pacific Ocean is 2807 miles, while the 

 shortest distance from the Atlantic to the Pacific 

 across the United States is 1152 miles, measured 

 from the neighbourhood of Charlestown, South Caro- 

 lina, to San Diego, California. The Canadian 

 boundary line from the Atlantic to the Pacific is 

 3898 miles in length ; the Mexican, from the Gulf of 

 Mexico to the Pacific, 1744 miles. The Atlantic 

 coast-line measures 5560 miles, the Pacific 2730 miles, 

 while that washed by the Gulf of Mexico is 3640 miles 

 in length. 



Blue Hill Meteorological Observatory has issued 

 its observations and investigations for the year 1919 

 as vol. lx.\xiii., part 4, of the .\nnals of the Astro- 

 nomical Observatory of Harvard College, U.S. .A. 

 The work has been done under the direction of Prof. 



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