26S 



NA TURE 



[July 19, 1894 



Alps, but it is rightly held that the man who goes through 

 a course of training among the crags of Cumberland 

 qualifies himself to taclcle the giants of the Alps or 

 Caucasus. Beginning with the tors on Dartmoor, the 

 would-be Alpinist can pass by easy stages to such climbs 

 as those of Deep Gill, Mickledoor and Xapes Needle, 

 and then complete his course of instruction on the Alps. 

 For convenience of reference, all the headings are 

 arranged in alphabetical order. It is easy, therefore, to 

 turn up information about hills or rocks which aflord 

 climbs, and to find the meaning of technical terms and 

 expressions. It would have been an advantage, however, 

 if .Mr. Smith had given a list of climbs in the order of 

 difficulty, for beginners would then know exactly where 

 to commence their mountaineering education. The book 

 is illustrated with twenty-three sketches by Mr. Ellis 

 Carr, and five plans. It will doubtless increase the number 

 of climbers, and the many admonitions it contains ought 

 to keep down the mortality from what someone has called 

 the •' greasy pole " exercise. 



LETTERS TO THE EDITOR. 



[lie Editor aoes not hoid kinnel/ respomibU for opinions ex- 

 pressed by his correspondents. Neither can hi undertake 

 to return, or to correspond tvith the writers oj, rejected 

 manuscripts intended for this or any other part o/Naturb. 

 No notice is taken of anonymous communications. ] 



Trituberculy and Polybuny. 



It is a matter of regret to me that so clear-headed a naturalist 

 as Dr. Forsylh Major should have misunderstood what I thought 

 to be clear intelligible language. 



In his letter (Nature, May 31) Dr. Forsyth Major declares 

 that, in my paper on the Stonesfield mammalia, I stated that 

 he has expre^sed views in his paper on Squirrels {P. Z. S. 1893) 

 the very reverse of those recorded by him in that paper. All 

 that I have said about Dr, Major, whose paper I read after 

 writing mine, is " Dr. Forsylh Major does not favour this view, ' 

 viz. that all the various forms of lower molars of Ditrematous 

 mammals can be derived from the tubercular-sectorial type. I 

 shall be glad if Dr. Forsyth Major w ill either state that he does 

 favour this view, or withdraw his charge of misrepresentation. 



Again, I think. Dr. Major has misunderstood my words when 

 he proceeds to declare that I have made " some obviously con- 

 tradictory statements " in my paper on the Stonesfield mam- 

 malia, and in my letter to Nature of May 3. The object of 

 my remarks on the primitive mammalian tooth in my paper, was 

 to show that that part of the " tritubercular theory " (as lately 

 set forth by Profs. Cope and Oaborn) which seeks to explain the 

 tubercular-sectorial tooth as having arisen — within the mam- 

 malia phylum — from a single cone through a liiconodont stage is 

 beset with weaknesses and improbabilities which render it unten- 

 able. The view there expressed that the Pro-mammalian 

 molars "were of an indefinite multitubcrculate pattern," or, in 

 other words (used in my letter), that they were "provided with 

 many cusps not placed in one line," is not inconsistent with the 

 admission that the common ancestors of the Marsupials and 

 Placcntals — ^and even (if wc accept Prof. Osliorn's latest sl.aic- 

 mcnis) of the so-called "multituberculata" — may have already 

 developed tubercular-sectorial lower molars, ,ind perhaps tri- 

 tubercular upper molars. Dr. Forsyth M.'ijor, whose careful 

 observations deserve great consideration, has argued, in his 

 letter of .M.iy 31, very forcibly against this " working hypo- 

 thesis." 1 think it only right to say that the views expressed by 

 him arc i Icimt.il with those which have been urged on iiic 

 privately, and also expressed in lectures, by Prof. Lankcslcr, 

 under whose direction I made my investigation of the Stones- 

 fi<*!d jaws. 



The theory I support, then, merely comes lo thi, : that many- 

 cuspctl teeth of indefinite pattern (such as those of Urnilho- 

 rl- ' • ' I ularscctorial lower and, perhaps, 



'' nc of which in turn gave rise to 



n ^.;riUe serially luberculated pattern 



(1 .). Prof. fJsborn declared that hehadevi- 



'li r iitep. The one mistake to which I plead 



guiliy i> Liui of having apparently endorsed in my letter Prof. 



NO. 1290, VOL. 50] 



Osborn's view on this latter point. In reality I wished to be 

 understood as admitting temporarily — and until further evidence 

 comes to hand — a statement which I was not in a position to 

 combat by the use of my own observations. 



Oxford, June 4. E. S. Goodrich. 



A Review Reviewed. 



I .4M rather astonished at the criticism of my use of the terai 

 mineraliser in my book on the " Economic Geology of the 

 United States, " made by a reviewer in a recent number of 

 Nature. Surely the sanction of the Century, Webster, and 

 Worcester dictionaries, besides several scientific works, should 

 be considered as warranting my use of the term, unless some 

 very serious objection can be urged. 



Since I am writing on the subject, I may say what perhaps 

 should have been said in my preface, that the mineralogical 

 part of the book, to which exception is taken by the reviewer, 

 was not intended to teach mineralogy, but to call attention to 

 a new aspect of the subject — the economic. The students for 

 whom the book was mainly written, those at Cornell University, 

 have, when they begin the study of economic geology, already 

 studied determinative mineralogy and blowpipe analysis, and 

 they have also studied rock-forming minerals from the geo- 

 logical standpoint. Here is the third standpoint, and experience 

 in teaching shows that the plan is not superfluous. 



Objection is also made to the absence of illustrations. But 

 this is intenti0n.1l, for I believe the class-room is the place for 

 these. There we can use large illustrations, lantern-slides, and 

 original maps and sections, which are vastly better than text- 

 book diagrams. 



I wish also to make an acknowledgment. As the reviewer 

 points out, and as others have done before him, the chapter on 

 mining terms and methods is weak and in places inaccurate. It 

 was a serious error on my pan (for which the book has suffered) 

 not to have submitted this chapter, upon which I have oidy 

 second-hand knowledge, to some specialist for revision. At 

 present the only thing that can be done is to promise the 

 elimination of the objectionable parts in a second edition, if one 

 is called for. ' Kali'H S. Tarr. 



Cornell University, Ithaca, N.Y., June 29. 



I WILL reply seriatim to the various points of Prof. Tarr's 

 letter. 



(1) Term "Mineraliser." — I still think the word objec- 

 tionable in the sense used by Prof Tarr. To most people it 

 probably conveys the idea of something which converts or helps 

 to convert another substance into a mineral. Mow can sulphur 

 be said to "mineralise" silver by combining with it? both 

 the elements already exist as minerals in nature ; and one 

 might just as well say that the silver mineralised the sulphur. 



(2) Mineralogical part of the book. — I'rof. Tarr states that the 

 object of this part of the book is not lo te.ach mineralogy, but 

 to call the attention of students lo the economic side of the 

 question ; but this is no excuse for loose and careless writing, 

 instances of which are far too numerous. We re.ad on page 1(3 : 

 " When a metal is combined with silica (SiO.^), a silicate is 

 formed." "Ores considered from the economic standpoint 

 occur in beds or in veins " (p. 17) ; this would lead the student 

 to infer that no other modes of occurrence are known. Iron 

 pyrite "grades into copper pyritc, but when there is much 

 copper present the colour becomes more golden " (p. iS) 

 "Grade" as a neuter verb does not appear in my edition of 

 Webster, but it probably is intended to mean " gradually passes 

 into." This reading is conlirmeil on page 22, where we find 

 "copper pyrites, which is in reality a sulphide of iron and 

 copper combined, the proportion varying from an exceedingly 

 cujiriferous variety (chalcopyrile) to pure iron iiyrile.s." Limonite 

 is spoken of as " the rust of hematite " (p. 19). Tin ore " is 

 found both as tinstone, in coarse granites or pegmatites, and as 

 stream-tin " (p. 25). Is not stream-tin a form of tinstone, 

 and may not tin ore be found in fine-grained granite and in 

 slate ? 



Judging from the paragraph on page 26, the author is unaware 

 of the existence of any oxidised ore of nickel. The student 

 docs not ol;tain a correct idea of dolomite by being told that it 

 is carbonate of lime " combined chemically with magnesium' 

 (p. 10). I think that these instances, and others might be 

 quoted, justify my remarks. 



(3) J'aucity oJ illustrations.— HVtoi. Tarr had adhered to 



