4i8 



NATURE 



[_Sept. 13, 1877 



elegant solutions which were constantly being given. 

 We have the number for October, 1862, before us, in 

 which are Questions 131 2 to 1320 proposed under six 

 different names ; we turn to the number for the current 

 month, and the questions range from 5387 to 5419 from 

 as many individual proposers, whose names are given. 

 Here is evidence that a want has been met, and that 

 there is considerable vitality in this direction ; indeed, 

 we may remark that this is the sole English periodical 

 (since the demise of the Ladfs and Gentlciuati's Diary) 

 to which mathematicians can send high-class problems. 

 University and college examinations swallow up a great 

 deal of what is produced by residents at the universities, 

 but these pages are open to all comers. 



It soon occurred to us that here was a great mass of 

 useful work being done and yet not producing the full 

 benefit it might do if it were reproduced and published in 

 a separate volume. The editor at once fell in with our 

 views ; indeed we found that the like idea had occurred 

 to himself. There were, however, supposed pecuniary 

 and other difficulties to encounter, but at last these were 

 got over and the work, after one volume had been pub- 

 lished, took its present form, which is now a conspicuous 

 one on many a student's shelf The fact that now their 

 solutions would be treasured up in this more desirable 

 shape seems soon to have led our foremost mathe- 

 maticians to give in their adhesion, and as we run over 

 the long list of contributors prefixed to the volume before 

 us, there is hardly a name familiar to us which is not to 

 be found there. France, Italy, and America also, are 

 fairly represented. Ladies, too, there are, showing that 



" the gay determinant 

 For (them) its rows exclianges, 

 While Hamilton's weird delta turned (v) 

 O'er all the symbols ranges." 



It says very much for the ability, in more directions 

 than one, of the editor, that he has nursed the bantling 

 which was handed over to his care more than sixteen 

 years ago into the vigorous and lusty athlete of to-day. 

 Nothing mathematical comes amiss to his net, but we 

 may say that though the Dii majores roam about in their 

 own special pastures, he has a marked predilection for 

 the line taken up and well-worked out by Messrs. Wool- 

 house and Crofton, i.e., of probability in its many 

 applications. 



It only remains to say that the " Reprint " is more than 

 a reprint, for it contains about as much more original 

 matter as appears in the monthly paper. Space is found 

 for detached papers and notes, and for alternative solu- 

 tions, often of equal, if not greater, interest, than the 

 previously published matter. 



There are occasional parenthetical notes — we think it 

 should be more clearly indicated who is responsible for 

 these, as they are often valuable ones. 



The training the printers have gone through in getting 

 out these solutions has placed them on a high level as 

 printers of mathematics, and the volumes of this series 

 reflect great credit upon them. 



CroiiicoH Cientijico Popu/ar. I'or D. Emilio Huelin. 



Vol. I. (Madrid: 1877.) 

 We perused this volume with interest and pleasant 

 surprise ; we were pleased at finding it to be an excellent 

 and well-written review of all new occurrences in the 

 scientific world, and wc were surprised to see such a work 

 emanate from a country which hitherto has contributed 

 but too small a share towards the progress and welfare of 

 science. If we place Turkey at the head of the list of the 

 most unscientific countries in Europe, Spain and Portugal 

 certainly come second on that list ; it is gratifying, 

 therefore, to see some sign of improvement. We con- 

 gratulate Senor Huelin on his valuable publication, which 

 is one of the best of the kind that has yet come under 

 our notice. The arrangement of the contents of the 



volume is particularlygood. The first fevvchapters are dedi- 

 cated to generalities and the philosophy of sciences ; some 

 of them contain detailed lists of all scientific publications 

 in the world. Then follow numerous chapters relating to 

 the latest discoveries, inventions, theories, &c., on the 

 domains of physics, chemistry, astronomy, meteorology, 

 mineralogy, and geology ; the chapters of the physical 

 section alone numbering no less than eighteen, and those 

 of the chemical section as many as twenty. Any occur- 

 rence at all worthy of record up to the end of last year is 

 faithfully mentioned in the book. The second volume 

 will contain the biological and mathematical sciences. We 

 wish Senor Huelin and his publishers every success with 

 their valuable addition to scientific literature. 



Die Katuikidfle. Band 21. "Die Insekten" (ist part): 

 " Der Organismus der Insekten." With 200 original 

 Woodcuts. By Dr. Georg Mayr. (Miinchen : R. 

 Oldenbourg, 1877.) 



The importance of an examination of the internal as well 

 as the external anatomy of insects has unhappily not 

 hitherto engaged the attention which it deserves at the 

 hands of British entomologists. It is a fact v/hich 

 cannot be disputed that by far the greater portion of that 

 energy which our country has exhibited in the investiga- 

 tion of this branch of natural science has been devoted 

 to the mere founding of types, and in consequence but 

 little light has been thrownupon the ever-increasing array 

 of problems which puzzle the biologist. 



In studying the affinities of insects it is quite as 

 important, and in all probability more so, that the 

 internal structure and the embryology of insects should 

 be known, as the external characters and the meta- 

 morphoses ; it is therefore with unmixed pleasure that we 

 v/elcome the appearance of Dr. Mayr's admirable and 

 ably-illustrated treatise. 



It would be impossible here to give even an outline of 

 the vast series of facts which the learned author has 

 brought together, nothing relative to the organism of 

 insects being regarded as too insignificant for careful and 

 unwearied research ; as an instance of the thoroughness 

 of his labours we would especially call attention to his 

 interesting observations on the action of the legs of insects 

 when walking, a point which he seems thoroughly to have 

 studied and which he has amply illustrated, although 

 many students would probably have regarded it as a 

 matter of little moment. In fine, the entire volume is 

 most valuable, and should be esteemed as a necessary 

 hand-book, not only by every entomologist, but by all 

 who have the interests of natural science at heart. 



A. G. B. 



LETTERS TO THE EDITOR 



[T/ie Editor does not hold liimself responsible for opinions expressed 

 by Ins correspondents. Neitlter can lie undeitake to return, 

 or to coiTCspond with the writers of, rejected manuscripts. 

 No notice is taken of anonymous communuations. 



The Editor urgently requests correspondents to keep their letters as 

 short as possible. The pressure on his space is so great that it 

 is impossible otiierwise to enstire tlie appearance even of com- 

 7nunications containing interesting and novel facts.\ 



Glacial Geology of Orkney and Shetland 

 A RECENT visit to Orkney has brought forcibly before me 

 certain points of the highest interest in modern glacial geology, 

 upon whicli, I believe, the state of the surface deposits in these 

 islands is calculated to throw considerable light. 



I may premise that .although I am perfectly well acquainted 

 with all the usual glacial phenomena of the North of Scotland, 

 as described in Geiltie's and other works, I am not a sufficient 

 practical geologist to speak with positive certainty, though I think 

 I know enough of the subject to establish n. priinA facicc-M^ for 

 what I have seen with my own eyes, and which I put forward 

 in the hope that more competent observers may direct their 



