386 



NATURE 



[January i8, i<>ij 



•omi" dpiurre of jjrndntJon In the»e respect*; but thf fomm 

 includ«<l in or%vnU\\\i probably have n smaller dev«-h»pmfnt 

 of \\\f throat-rufl. Whether these features are of specific 

 value iH doubtful. In his latest rommunication on the 

 subject Mr. Lydekker regarded erskinei as equivalent to 

 the typical race of orienlalis. 



Mr. C. H. O'Donoghuk contributes to the current 

 number of the Quarterly journal of Microscopical Science 

 (vol. Ivii., part ii.) an interesting memoir on the mammary 

 glands of the Australian marsupial cat (Dasyurus). The 

 gland arises as outgrowths from the follicles of certain 

 hairs which appear on the rudiment of the teat, and these 

 hairs, which subsequently disappear, are equal in numlx-r 

 to the main milk ducts in the adult teat. The author also 

 discusses the causes which contribute towards the hyper- 

 trophy of the mammary gland during pregnancy and at 

 other times, and concludes that the stimulus to growth is 

 not a nervojs one, but is due to an internal secretion or 

 hormone circulating in the blood. It has long been known 

 that there is an intimate correlation between the presence 

 of the corpora lutea in the ovary and the fixation of the 

 fcBtus to the uterine wall, and it is supposed that the 

 corpora lutea are glandular bodies the secretion of which, 

 conveyed by the blood, stimulates the wall of the uterus 

 to undergo the necessary changes in preparation for the 

 reception of the foetus. Mr. O'Donoghue gives good 

 reasons for believing that the secretion of the corpora lutea 

 also stimulates the mammary glands, and thus causes their 

 enlargement, although other factors are probably re- 

 sponsible for causing the actual secretion of milk. We 

 note that Mr. O'Donoghue makes use of the German 

 term " .Anlage," where, as it appears to us, " rudiment " 

 would be greatly preferable. 



The third volume of the Indian Forest Records begins 

 with an important part prepared by Mr. R. S. Troup, in 

 which the author examines statistical and other informa- 

 tion regarding the teak forests of Burma. It is noted that 

 the limits of natural teak forests, except to the east, lie 

 within the province. The total area of teak forests cannot 

 be computed, but with regard to the reserved forests, 

 exceeding 25,000 square miles, rather less than one quarter 

 is returned as teak-bearing (which implies about 6 per 

 cent, of the growing stock). The greater part of the teak 

 forests may be designated either as " upper mixed," 

 occupying hilly country and characterised by the prevalence 

 of bamboos, or as " lower mixed," on flat ground. In 

 the former class distinction is drawn between dry forest, 

 where Dendrocalamtis strictus is a comqion bamboo, and 

 moist forest, which often contains Dambusa polymorpha 

 or Cephalostachyum pergracile. According to available 

 figures, teak trees require no to 190 years to reach a girth 

 of 7 feet, upon which basis the exploitable age has been 

 fixed at 150 to 180 years. 



Peterniant's Mittcilungcti for December, 1911, contains 

 a map of the world to show the state of our knowledge 

 regarding the relief of the earth's surface. Five grades 

 are employed, both on land and sea areas, to classify the 

 data according to their completeness. Over the oceans the 

 number of soundings in a 1° square (2° beyond the 6oth 

 parallel) is used as the basis of classification, but on land 

 the scale on which maps have been published is adopted on 

 the assumption that the density of points of which the 

 altitudes have been determined, and the accuracy of the 

 results, are comparable with the scale on which maps are 

 published. A close investigation of every land area to 

 determine the density of determined altitudes and the 

 accuracy of the determinations would be a long piece of 

 NC. 2203, VOL. S8] 



work, but it u the oaly saticfactory way of arrivir»(< 

 rhe pretent flate of our knowledge of the earth's rrii' 



Mr. E. K. SuvoRor explored the Commander Islands in 

 the summer of 1910, and his observations are described in 

 the Izvestiya of the Russian Geographical Society (No. 6. 

 iqii). The group consists of four islands, the well-known 

 Bering and Copper Islands, and two small ones 

 having no fresh water, are inhabited only by innui: 

 birds. Bering Island consist* of two parts, a norihtr: 

 low, and covered with tundra, and studded by a few h: 

 not reaching 600 feet, and a southern, which is a 1 

 mass of elevations in chains and groups attaining- a : 

 of 2200 feet, and is almost inaccessible except along the 

 coast. Volcanic tuff is the prevailing formation. The 

 northern tundra has been formed by the silting-up of lak' 

 which were originally inlets from the sea, and have be* 

 cut off from it by upheaval of the land. In some places 

 may be noticed two, or even three, clearly marked terraces. 

 One of the lakes still in existence, the Sarannoie, is sup- 

 posed by the natives to be of unfathomable depth, hut 

 Mr. Suvorof found its deepest hollow sounded only 57^ fe' 

 Nor are the reports of its extraordinarily low temperatu- 

 correct, for on July 4 the temperature fell from 54-3* F 

 at the surface to 50°. Copper Island has a more compi 

 cated geological structure. Tuff and tuff conglomer;'. 

 certainly predominate, but dacite, basalt, augite, anu 

 andesite occur on the north-east coast. The line of coast 

 is determined by a fault. The inhabitants of the island 

 Aleuts, with an admixture of several other elements, kt- 

 a few cattle and pigs and catch salmon, cod, blue fox- 

 and sea-otters, the last almost exclusively at Copp 

 Island. 



Among the very useful summaries of the geology of 

 British districts, prepared by specialists and published in 

 the Proceedings of the Geologists' Association, should be 

 mentioned those on " The Districts around Settle and 

 Harrogate," by Prof. Percy F. Ken-lall (vol. xxii., 1911, 

 p. 27); on "The District around St. David's, Pembroke- 

 shire," by Mr. J. F. N. Green (ihui , p. 121); on "The 

 Neighbourhood of Fort William," iv Mr. E. B. Bailey; on 

 "The Neighbourhood of Broadford, Skye," by A. Harker ; 

 and on " The Geology of the Cuillin Range," by Mr. 

 W. F. Gwinnell. The last three follow one another ir 

 part 4 of vol. xxii., pp. 179-214. The photographic illi^ 

 trations and the sections in these papers make theni 

 additionally serviceable to teachers. In plate xi. the famous 

 unconformity at the Arco Wood Quarry, Ribblesdale, is 

 reproduced, and the view of Ingleborough (plate xii.) is one 

 of the finest that we know. Prof. Kendall publishes (p. 37) 

 his conclusion that the Yoredale and Pendleside series are 

 really contemporaneous, a matter on which much more is 

 certain to be written. Mr. Bailey's paper includes a de- 

 scription of the " cauldron-subsidence " of Glencoe and of 

 the igneous history of Ben Nevis, where sinking is also 

 recognised, and where it accounts for the preservation of 

 the summit andesites in an encircling ring^ of granite. 



At the meeting of the Vienna Academy of Sciences on 

 November 30, 191 1, Prof. J. Hann submitted a work 

 entitled " Results of Dr. E. Glaser's Meteorological 

 Observations at Sana (Yemen)." The observations were 

 made between January and October, 1883, only, but as 

 no complete data for the interior of Arabia were previpusly 

 available, the present carefully made series is of consider- 

 able interest. By comparison with observations for corre- 

 sponding months at stations on the adjacent coast, and 

 the use of interpolation formulae, Dr. Hann was able to 

 deduce very approximate monthly and yearly values of 



