July 2, 1874] 



NATURE 



^7Z 



the oyster beds all over the world. It is n well-known fact that 

 oysters will not grow in certain localities where the conditions 

 are apparently exactly similar to otlier localities where they will 

 tlirive ; and the gradual change wrought by the sea in certain 

 jiarts of tlie coast mayj account, quite as much as overfishing, 

 for the gradual extinction of oysters. All beds are, however, 

 fislied much more extensively now tlian they were a few years ago, 

 and whenever one is discovered, it is quickly worked out, with- 

 out any consideration being given to the question of its 

 extent, and whether it is a newly-established bed or not. Amei'ica 

 now largely supplies us with oysters either in a fresh state or 

 preserved in tins, audit is calculated that in Maryland State 

 alone, 5.2S2 p;r.-ons are employed in dredging, and 10,947,803 

 busliels of oysters were taken in 1870-71 ; while the waters of 

 Virginia are said to be equally productive. In the great ojster 

 markets of Baltimore, where immense quantities of oysters are 

 tinned, over 10,000 hands are employed in thisbranchof the trade. 



A VALUABLE Contribution to zoology is furnished by a paper 

 published by Mr. Dall, on the birds of the Aleutian Islands, 

 especially of that portion of the region to the west of Oonalaska, 

 embracing the result of observations made during 1873 on 

 board the U.S. Coast Survey vessel, the Ynkon. As might 

 have been expected, the great majority of the species are water- 

 birds, particularly <7/c(7(/(r, upon the natural history of which Mr. 

 Dall throws much light, having been the first to collect eggs 

 of several of the species, and observe their habits during the 

 breeding season. The land-birds on this island are very few in 

 number, consisting of two kinds of hav.ks, one owl, a swallow, 

 and a wren, five finches, the raven, and ptarmigan. The total 

 number of species enumerated is forty-five. 



We have received the prospectus of a work entitled "The 

 Dominion of Canada ; comprehending a General Description of 

 the Confederated Provinces of British North America, and the 

 North-west Territories," by Henry Yoide Hind, M. A. (Mon- 

 treal : John Lovell.) The following are the leading sirbjects : — 

 I. Physical Geography of the Dominion. II. Climate and 

 Climatic Effects. III. Geological Features. IV. Travel and 

 Transportation. V. Agricultural, Forest and Mining Industries. 

 VI. Commerce, Manufactures, and Fisheries. VII. The Inha- 

 biiants. VIII. Government. IX. Socril Status. X. Miscel- 

 lanea. The iUustrations will consist of upwards of 250 engravings 

 on steel, chromoxylographs, woodcuts, &c. 



At present the principal source of income to the United States 

 from its acquisition of Alaska, and that which pays the larger 

 part of the interest on the original investment of 7,000,000 dols. 

 in its purchase, is derived from the fur-seal islands of St. Paul 

 and St. George, which constitute the Pribylov group, in the 

 Behring Sea. It is from these islands that the gi-eater number 

 of the skins of the fur seal as known in commerce are derived 

 the animals resorting to them in immense numbers every spring 

 lor the purpose of bringing forth their young. In 1870, an 

 Act was passed by Congress limiting the number to be killed at 

 100,000. The Alaska Commercial Company secured the lease 

 of the fishery, and has carried out the contract in apparent f^ood 

 faith. The condition of the islanders has been considerably im- 

 proved. Congress has authorised the appointment of a com- 

 mission to investigate the natural history and geographical distri- 

 bution of the fur seal. 



From the Monthly Notices 01 the Royal Society of Tasmania 

 for June, July, and August, 1S73, we learn that the Society 

 has been making an inquiry in reference to the stone imple- 

 ments of the Tasmanian aborigines, especially as to whether the 

 natives made use of these implements fastened to handles, after 

 the manner of axes or tomahawks. All inquiries on the subject 

 tend to prove that no true tomahawks were known to or faliri- 



cated by the natives ; they merely used sharp-edged stones as 

 knives. These were made sharp, not by grinding or polishitrg, 

 but by striking off flakes with another stone till the required 

 edge was obtained. As a very general, if not invariable, rule, 

 one surface only was cliipptd in the process of sharpening. They 

 were m.ade from two different kinds of stone — the one apparently 

 an indurated clay rock, the other contaiiring a large proportion 

 of silex. 



A WRITER in the Times complaining of the want of labels in 

 the Bird Gallery of the British Museum, states that " A young 

 and active Naturalist has been appointed specially to look after 

 this part of the collections." It is hoped that he will see that 

 all the specimens are furnished with labels. 



Some experiments of particular interest physiologically have 

 been undertaken by Dr. Worm M tiller, and are described by 

 him in I.udwig's Arbeiten (vol. viii. p. 159), an abstract of which 

 paper will be found in the London Medical Record for last week. 

 The author finds that the transfusion into the circulatory system 

 of an amount of blood three times as much as that normally con- 

 tained in the system does not cause any rise in the arterial blood 

 pressure, though the pulse-rate is reduced. The reduction of the 

 quantity of blood after transfusion, however, causes a rapid fall 

 in the blood-pressure, even when only half that added has been 

 removed. We think that the former of these resitlts is not diffi- 

 cult to explain, for the heart, being an engine with only a limited 

 capacity for work, it can only maintain a certain determinable 

 blood-pressure, depending on the bulk of its muscular parietes. 

 The introduction of an excess of blood to be circulated can 

 therefore act oirly in filling the system at the expense of the 

 velocity of the current, with a diminution in the rapidity of the 

 cardiac action. 



It may be of some interest with reference to the demand of 

 ladies to be admitted to the ordinary degrees of the University of 

 London, to note that at the recent distribution of prizes at Uni- 

 versity College the first and second places in the mixed class of 

 Jurisprudence were both occupied by ladies, Miss E. Orcne, who 

 two years ago took the prize in the class of Political Economy, 

 coming out first, while in the mixed diss of Political Econo.Tiy 

 a lady this year took the fourth certificate. 



Dr. W. G. Farlow has published in \.\ve American Journal 

 of Science and Arts an account of some investigations carried on 

 in the botanical laboratory of the University of Strasburg, illiis- 

 tialing a remarkable .asexual devcI'Jiiment from the prothallus of 

 rieris serulata. In the centre of the cushion or thickest part of 

 the prothallus were a number of scalariform ducts, the prothallus 

 bearing a number of antheridia, but no archegonia. From these 

 ducts a leaf is developed directly, after which a root is also deve- 

 loped, and last of all a stem-bud. A comparison was drawn 

 between this growth, which was observed in this species only, 

 and the buds produced in the ordinary way from the protonema 

 of a moss. Normally the prothallus of a fern is entirely des- 

 titute of vascular tissue of any kind. 



Dr. McKendrick (/??•;'/. Med. 7«/r;/,, June27, 1S74) hasmade 

 a contribution to the subject of the physiological antagonism of 

 medicines which has been so elaborately illustrated by the 

 works of Eraser and Cram Brown. He finds that while Bromal 

 causes an excessively copious secretion of saliva, Atropine quickly 

 arrests it, in rabbits. Possible practical applications of this dis- 

 overy in the treatment of various kinds of ptyalism in man are 

 at once thought of, and already cases of so-called success in the 

 salvation of pregnancy are recorded. 



In the Bulletin of the Buffalo Soc. Nat. Sci. No. 4, vol. i., 

 will be found a paper by Prof. Hartt on the geology of the 

 Lower Amazons. He determines, on palaeontological evidence, 

 that the gre.it plain of the Serra of Ercre is of Devonian age. 



