AucusT 8, 1 901] 



NA TURE 



;55 



repute will hold an even balance where boundaries 

 are sub judice. 



In the case of the Chile-Bolivia boundary, it appears 

 that the publisher also considers that Bolivia has no 

 territorial rights which Chile is bound to respect. 



Mr. Keane closes his work with an extensive and 

 valuable chapter on Brazil, a country which occupies 

 nearly one-half of the area of South America. His 

 remarks upon the "ethnical elements of the population 

 and their distribution " he considers of value in estimat- 

 ing the probable political future of the Republic. "The 

 triple fusion of aborigines, negroes and Europeans is 

 mainly confined to the .Atlantic States between the 

 Amazon estuary and Rio de Janeiro. Then follow the 

 States of San Paulo, Parana, Santa Catharina and Rio 

 Grande do Sul, with which must be grouped the vast and 

 relatively populous region of Minas Geraes. Here we 

 have no triple fusion, the negro element being every- 

 where mainly absent : but, as in Spanish America, an 

 amalgam of aborigines and whites . . . which constitute 

 the second section of the Brazilian people, distinguished 

 from the first by the absence of black blood. Lastly, the 

 aboriginal element tends to disappear in the direction of 

 the south, where the white element is continually 

 strengthened by direct accessions from various parts of 

 Europe, but especially Italy, Portugal and Austria." 



As to the above quotation, the State of Minas Geraes is 

 the most populous in Brazil, and the negro element is 

 everywhere in evidence : and instead of an " amalgam of 

 aborigines and whites," few of the inhabitants are free 

 from negro blood. Exclusive of the aboriginal tribes, 

 one seldom finds any traces of Indian blood among the 

 Brazilians except in the immediate vicinity of the banks 

 of the main River .\mazon. 



Notwithstanding a few details where we might disagree 

 with Mr. Keane, he has given us a most useful work of 

 reference ; but every reader at all familiar with South 

 American geography will regret that the maps are not 

 more trustworthy. GEORGE Earl CHURCH. 



ZONES IN THE CHALK. 



A TTENTION was directed in N.xture for April 26, 

 -'*- 1900, to Dr. .A.. W. Rowe's researches on the zones 

 of the White Chalk of Kent and Sussex. Dr. Rowe has 

 since published his observations on the White Chalk of 

 Dorset (Proc. Geol. Assol.,\o\. xvii. part i. 1901). .Aided 

 in the field as before by Mr. C. Davies Sherborn, the 

 author has made a particular study of the higher 

 portions of the Chalk which commence with the zone of 

 Rhynchonella Ci/vieri. 



Those who are familiar with this portion of the Dorset 

 coast, or have read Mr. .Aubrey Strahan's explanatory 

 memoir (published by the Geological .Survey), know how 

 faulted and crushed are the strata in many places, and 

 how difficult or impossible of access are many portions of 

 the cliffs. Undaunted, however, by these obstacles, or 

 by the hardness of the Chalk and the trouble in extracting 

 and preserving the often shattered fossils. Dr. Rowe and 

 Mr. .Sherborn " have been able to fix, with varying 

 degrees of accuracy, the limits of nearly every zone," and 

 to record from each a characteristic fauna. While con- 

 firming the general conclusions of Dr. Barrois, they have 

 amplified our knowledge to a remarkable extent, and 

 have had the satisfaction of determining the presence, 

 hitherto unsuspected in the region between White Nothe 

 and Studland Bay, of the higher Chalk zones of Ailino- 

 cainax guadratus and Bcleinnilella tnucronaia. 



That zones in the Chalk are purely zoological divisions 

 is thoroughly borne out in this paper, and although it is 

 remarked that " nothing but rigid collecting gives one 

 the faintest chance of obtaining the junction between the 

 various beds," it is evident that no more definite 



NO. 1658, VOL. 64] 



boundary is to be expected between zones than that 

 which in human chronology separates one century from 

 another. Here and there particular flint-bands, the 

 nodular character or the colouring of the Chalk afford 

 local guides for marking approximate junctions or for 

 tracing horizons from place to place amid the complex 

 disturbances of the strata : and these have been carefully 

 noted. Dr. Rowe, indeed, felt some "anxiety to find a 

 lithological feature " whereby to permanently mark the 

 planes of division he took, but this was seldom possible, 

 nor could it reasonably be expected in such a compara- 

 tively uniform series of strata. Nevertheless, the results 

 of Dr. Rowe's painstaking work have been in many 

 instances permanently recorded in a series of beautifully 

 executed plates prepared from photographs taken by 

 Prof H. E. Armstrong. Diagrams accompany these 

 plates to show the positions of the several zones and the 

 limits assigned to them. No higher testimony to the 

 value of zones has, perhaps, ever been given in this 

 country, for the authors have had a veritable geological 

 puzzle to deal with, and they have interpreted it by 

 means of their long experience of Chalk fossils and by 

 assiduous collecting. By these means the knowledge 

 elsewhere gained where the sequence is unbroken has 

 been applied with marked success, and the progressive 

 changes in the life-history of the Chalk have been found 

 to correspond with a precision that could not have been 

 expected in strata deposited under more varying condi- 

 tions. While the zones are marked out within narrow 

 limits by certain dominant species, yet where these 

 zonal forms are absent the "zones are often as accurately 

 defined by their associated guide-fossils." These are 

 noted with reference to Dorset. 



It may be observed that, with the exception of 

 Marsiipites, Actinocainax quadrat us and Belcvuiitella 

 mucronata, the dominant forms are not confined to the 

 zones they characterise. The author makes some 

 remarks on the varying position of the layers described 

 as Chalk Rock. No doubt any type of rock may be found 

 at any horizon, but it must be remembered that the limits 

 assigned to Chalk zones are approximate. There is no- 

 where any real boundary, and even some dominant types 

 may have existed in abundance longer in some areas 

 than in others. H. B. W. 



THE ORIGIN AND HABITS OF THE 

 BACTRIAN CAMEL. 



OF few of our larger domesticated animals is the 

 origin so buried in mystery as is that of the 

 camels. Till a few years ago, indeed, naturalists were in 

 doubt whether the two-humped Bactrian species was 

 really a native of the countries where it is now kept in a 

 domesticated condition. The probability was, however, 

 all in favour of such being the case ; and the recent 

 discovery of remains of fossil camels in several parts 

 of Europe, as well as the occurrence of such remains in 

 Asia, aftbrd strong corroborative evidence that eastern 

 Europe and northern Asia formed the original habitat 

 of the wild Bactrian species. 



The subject has recently been discussed in Globus for 

 May 2, 1901, by Dr. A. Xehring, of Berlin, who e.x- 

 presses himself in favour of the view that some, at least, 

 of the two-humped camels which roam at liberty over 

 the wastes of the Gobi are indigenously wild animals. 



Years ago the occurrence of remains of fossil camels 

 [Cainelus sivalensis) was recorded by Falconer and 

 Cautley in the Tertiary strata of the Siwalik Hills of 

 northern India. The dentition of this species is numeri- 

 cally the same as in the two living members of the group ; 

 and from this circumstance, coupled with the well-known 

 affinity between the extinct fauna of the Siwaliks and 

 that of Africa at the present day, it is not improbable 



