36 



NATURE 



[NoVEiMBER 9, 189; 



! 



when the collectors work a grove they should ba made to plant 

 a certain number of tree?. Only by such means, and by adopting 

 a chemical mode of coagulation, can the rubber production of 

 the Amazon territory bi increased in quantity and improved in 

 quality. 



Mr. Vernon Bailey has prepared a report, for the U.S. 

 Department of Agriculture, on the haunts and habits of the 

 soermophiles, known in America as gophers or ground squirrels, 

 inhaUting the Mississippi Valley region. Five distinct species 

 of the gsiius Spennophllus inhabit this region, and four are re- 

 stricted to it. On account of the immense damage done to 

 crops by these mammals, several States have endeavoured to 

 exterminate them, and they have formed the subject of in- 

 vestigation at a number of agricultural colleges and experi- 

 mental stations. The increase of the pest is probably due to the 

 thoughtless destruction of its natural enemies. We learn that 

 no less than sixteen of the seventy-three species and sub-species 

 of hawks and owls found in the United States are known to 

 prey on the various members of the genus Spermophilus. 

 Among mammals, the spermophile's enemies include the badger, 

 fox, coyot, wild cat, and weasel, all of which are hunted and 

 killed for sport or because of poultry-yard depredations. In 

 several States immense amounts of money have been paid as 

 bounties for the destruction of the pest, but the results are far 

 from satisfactory ; and it is evident that a bounty is only a 

 temporary expedient for the extermination of these or any other 

 animals. Mr. Bailey says that in many ways spermophiles 

 render valuable service to the farmer, so he does not recommend 

 a complete destruction of them. The evil which they do to 

 crops, however, is very considerable over more than two-thirds 

 of the United States ; hence there is a general demand for some 

 economical means of destroying them. The animals can, of 

 course, be shot, and in this way limited areas may be freed from 

 their ravages. Fumigation and trapping have also been em- 

 ployed with more or less success ; but the most effective 

 and quickest results have been obtained by placing in the bur- 

 rows a bunch of rags or waste saturated with carbon bisulphide, 

 and closing up the hole. The information on this point given 

 by Mr. Bailey should be of use to agriculturists ; indeed, the 

 whole of the bulletin is of high importance. 



At the request of the Royal Academy of Science in Vienna, 

 Prof. V. Hirbel undertook a geological tour this season in 

 Thessaly. One or two short reports from him are published in 

 the journal of i\\Q .Mathematics natur^idssensch. C/asse {No. 20, 

 October 12). Respecting the geology of Northern Greece, he 

 writes that calcareous formations of the Flysch have the most 

 extensive outcrop on the three parallel chains of the Pindus 

 range. Dykes of serpentine intrude through the Flysch, and 

 occur as flows interbedded with the overlying Cretaceous lime- 

 stones. The age of the much larger intrusive masses of ser- 

 pentine in the sandstone zone of the upper Peneus has not yet 

 been definitely ascertained. 



In the "Proceedings of the U.S. National Museum" 

 (vol. xvi. pp. 471-478, pi. 56), Mr. William Healey Dall de- 

 scribes a "Sub-tropical Miocene Fauna in Arctic Siberia." 

 This fauna consists of a few well-preserved specimens of mol- 

 luscan genera, Ostrea, Siphonaria, Cerithium, &c., which were 

 found in 1855 by a member of the "Ringgold and Rodgers 

 Exploring Expedition in the North Pacific." The fossils occur 

 in Miocene sandstones of the Sea of Okhotsk, which are 

 exactly like those of the Alaskan coast, and they are of interest 

 chiefly because ihey prove beyond doubt strong affinities of the 

 M'.ccene mollusca of these northern seas with species now living 

 in the warm seas of Japan and China. According to Mr. Dall, 

 the annual mean temperature of the waters in the Okhotsk area 

 liar, diminished by at least 30° to 40° F. since Miocene time. 



NO. 1254, VOL. 49] 



The U.S. National Museum has also published a report by Mr. 

 James [. Peck, on the pteropods and heteropods collected by 

 the U. S. Fish Commission steamer, Allmtross, during the voyage 

 from Norfolk, Va., to San Francisco in 1877-8. The pteropod 

 collections of this voyage are, for the most part, from the Cari- 

 bean and Panamaic provinces, and the material belongs almost 

 exclusively to the family Cavoliniidse. From none of the 

 deeper dredgings in the Pacific were pteropod deposit shells 

 reported, though at times the surface collections in the same 

 regions showed an abundance of the live animals. Mr. Peck 

 agrees with Agassiz that bottom distribution is largely deter- 

 mined by the course of the ocean currents, so that by means of 

 pelagic fauna and their bottom distribution, light maybe thrown 

 upon the course of the currents. To this cause Agassiz ascribed 

 the presence of Arctic pteropods along the New England coast, 

 from the course of the Labrador currents, and Mr. Peck believes 

 that the differences between the bottom and surface collections 

 of the Albatross on the voyage in the Gulf of Panama and at 

 the Galapagos Islands may be similarly explained. 



Some years ago, a discovery of fossil plants was made for the 

 first time in the Trinity Division of the Comanche series of 

 Texas. These have now been worked out in detail by Mr. 

 Wm. Morris Fontaine, who has published his results, together 

 with aseriesof illustrative plates, in the " Proceedings of the U.S. 

 National Museum" (vol. xvi. pp. 261-282, pi. 36-43). There 

 are twenty-three species described ; by far the greater number 

 are conifers belonging to the genera Abietites, Laricopsis, 

 Pinus, Frenelopsis, Sequoia, &c., a few Cycad genera, and a 

 new species of Equisetum are also present ; ferns are of exceed- 

 ingly rare occurrence, and angiosperms entirely wanting. 

 Seven of the species have been identified with forms from the 

 Lower Potomac deposits (Lower Cretaceous) of Virginia, and 

 several others show striking points of similarity with the same 

 flora ; four species agree with Wealden types. The whole 

 character of the " Trinity " flora, more especially the absence,, 

 so far as known, of angiosperms, seems in favour of Jurassic as 

 well as Cretaceous affinities. It certainly does not bear the dis- 

 tinct Cretaceous impress of the flora in the Potomac or Wealden 

 formations. Mr. Fontaine refers the "Trinity" flora, therefore, 

 to the base of the Cretaceous deposits in Texas, occupying a 

 slightly lower horizon than the very similar flora in the Potomac 

 deposits of Virginia. 



The recent geological history of the Arctic lands is discussed 

 by Sir Henry Howorth in the Geological Magazine. The 

 general conclusions to which he arrives are as follows : — (i) 

 During the Pleistocene period the Arctic lands, instead of 

 being overwhelmed by a glacial climate, were under compara- 

 tively mild conditions, and were the home of a widely-spread 

 and homogeneous fauna and flora, constituting, perhaps, the 

 best defined life-province in the world. (2) Since Pleistocene 

 times the climate of these Arctic lands has been growing more 

 and more severe, resulting in the extinction of a portion of 

 their vegetable and animal inhabitants. (3) While one portion 

 of this Pan-Arctic fauna and flora still remains largely homo- 

 geneous, another portion has become differentiated by evolution 

 in Northern America and Northern Europasia, into the Nearctic 

 and Palrearctic regions respectively. (4) The true and the 

 only glacial climate which we know to have prevailed in the 

 Arctic lands was not during the so-called glacial age of geolo- 

 gists, that is during"the Pleistocene period, but in that which is 

 now current, and which is the product largely, if not entirely, 

 of changes of level in the earth's crust which have occurred 

 since Pleistocene times. 



The " Geology of Dublin and its Neighbourhood" has found 

 a clear interpretation at the hand of Prof. Sollas, of Dublin Uni- 

 versity [vide Proceedings of the Geologists' Association, August, 



