394 



NATURE 



\Sept. 12, 1872 



Nature of January' 13, 1S70, and the subsequent correspond- 

 ence. The violet of the primary bow passed into red at its 

 concave edge, and within this violet-red arc there was a faint 

 appearance of prismatic colours, blue or green (and I think 

 yellow), and then a distinct red arc, and within this again yet 

 another very faint red arc. Between these last two the other 

 colours of the spectrum, if they existed, were too faint to be 

 seen • but the impression given by a coup iVail was that of three 

 complete series of colours. There was nothing beyond the red 

 on the outside of the primary bow, except, of course, the second- 

 ary bow, at some distance. 



This is the phenomenon alluded to by Mr. Justice Grove, in 

 his letter to Nature of January 20, 1870, in which he queries 

 whether these colours are repetitions of the spectrum, such as 

 are suggested by Sir John Ilerschel. Your correspondent, Mr. 

 C. J. Munro {Natukk, February 3, 1870), appears to regard 

 them as analogous to " Newton's Rings." I should much like 

 to see the point more fully elucidated. Is it established that 

 under no circumstances can the spectroscope show visible tays 

 beyond the violet ? George C. Thompson 



Cardiff, Sept. 8 



Cat's Teeth 



I HAVE in my collection the skull of a cat, which has the 

 peculiarity of possessing an extra molar tooth on the left 

 maxilla ; this tooth is tricuspid, and is situated between the last 

 premolar and the carnassial tooth, on their interior side, so 

 that it does not disturb their normal position. Will some of 

 your readers inform me whether this is not very unusual ? and 

 whether from its position it does not overthrow Professor 

 Owen's theory, that the two premolars are respectively third and 

 fourth ? 



R. Lydekker 

 Harpenden, Sept. 2 



DANISH EXPEDITION TO THE FAROES 



'"PHE United Steamers Company {forenedc Dampskib- 

 -!■ schkah) in Copenhagen, having got a grant from the 

 Government for the exploration of the Faroe coal-fields, 

 is about to send an expedition to these islands, for the 

 purpose of scientifically examining into the extent of the 

 coal-fields in the north of Siideroe, and discovering in 

 what manner coals may be best transported from that 

 island to Copenhagen. 



Besides having in view commercial purposes, the ex- 

 pedition will be accompanied by men of science, who will 

 investigate the natural history of these little-known islands. 

 The Government has asked Prof. Johnstrup to visit the 

 ^ different coal -fields on the southern island, and to inves- 

 tigate the geological features. The managers of the steam 

 company, represented by Consul Koch, have also kindly 

 allowed the writer of these lines to accompany the expe- 

 dition for zoological purposes. 



The geological features of the islands are best known 

 from Forchhammer's researches, published in the " Trans- 

 actions of the Danish Society of Sciences" (1828). The 

 rocks of the Faroes are for the greatest part of volcanic 

 origin, dolerite-porphyry being found in large masses in all 

 the islands. Coal sediments are only to be seen in the 

 south (Si-ideroe), and in the little islands of Myggenas 

 and Tindholm. To what formation these beds 

 belong has not been cleared up, as fossils have hitherto 

 not been discovered. But as the coal-fields of Iceland 

 and Greenland, in which fossil plants have been found, 

 belong to the miocenc-tertiary period, it is very probable 

 that those of the Faroes belong to the same formation. 

 The researches which now are to be made by Prof. John- 

 strup and his assistant, Cand. Geisler, will, we hope, throw 

 further light upon the nature of these deposits. 



The fauna of the islands, as far as the vertebrates ar.> 

 considered, was already tolerably well known at the 

 beginning of this century, as may be seen from Landt's 



'' Beskrivelse over Facriierne," published in 1800. The 

 only wild mammals inhabiting the interior of the island^ 

 are a few species of the genus Mas, which follow man's 

 steps wherever he goes. But the shores of the Faroes 

 are visited by a large number of Pninipt-dia and Cetaci.\-i, 

 from the capture of which the inhabitants have every year 

 a good profit. The birds — those inhabiting the rocks of 

 Store and Lille Dimon, as well as those of some of the 

 other islands— have been made known by Graba, and, so 

 far as they also occur in Iceland, by Faber. Later pub- 

 lications, especially by Swedish authors, are well known 

 to have thrown much light on the natural history of these 

 inhabitants of the north. Reptilia and Amphibia do not 

 occur at all in the Faroes ; but fishes of various species 

 come to the shores and ascend the rivers in considerable 

 numbers. They have been collected with great zeal by 

 Sysselman MiiUer, of Torshavu, who has sent a list and 

 specimens of all the species known to him to the zoological 

 museums of Copenhagen. The lower animals are less 

 known ; we have lists of cchinoderms and molluscs by 

 Liitken and Morch, and we know something about the 

 worms from the investigations made there by Prof. Oscar 

 Schmidt, who for a short time visited the Faroes. 

 The writer of these lines hopes to gather further informa- 

 tion about the lower animals by dredging on the shores of 

 the islands ; and, while collecting the fishes for the 

 Munich Museum, he will continue his researches into 

 the natural history of their parasites. 



The expedition will leave Copenhagen early in Septem- 

 ber, and, when returning from the Faroes, may perhaps 

 pay a visit to a Scottish port. 



RUD. V. 'WlLLEMOES-SUH.M 



Copenhagen, Sept. 4 



NATURAL HISTORY EDUCATION AT 

 HARVARD UNIVERSITY 



"VXrE reprint the following interesting article on the 

 ' » scientific instruction given in Harvard University 

 from the pages of the Ami'rican NatiD-alist : — 



The changes which have been made in the depart- 

 ments of Natural History at Cambridge within the last 

 two years have been very great, greater perhaps than in 

 any other school within the same time. As there are 

 many persons of both sexes who are seeking opportuni- 

 ties for study such as the University now offers, we give a 

 sketch of the plans of education in the dilTerent schools 

 as far as they concern the student of natural history. 

 There are five schools in the University where natural 

 history is taught : the College, the Museum of Compara- 

 tive Zoology, the Botanic Garden, the Scientific School, 

 and the Bussey Institution. Let us trace in a general way 

 the course of a student in these departments. 



The student who enters the college to-day is no longer 

 compelled to follow the one uniform road over which 

 the boy of twenty years past had to go ; after his first 

 or freshman year, he may begin to turn himself into 

 the paths of natural science. At the commencement of 

 his second year he may begin his studies by courses 

 which lay the foundations of a knowledge of chemistry, 

 tatight in the laboratory ; of physical geography, geology, 

 and meteorology, taught by text-books, lectures, and ex- 

 cursions in the field. The time allowed for these studies 

 during the year is estimated at twelve hours per week. 

 It is expected that the student will in this year lay the 

 foundations for the work he miywish to do during the 

 following years, by getting that general idea of the physics 

 of the globe which forms the necessary basis for the work 

 of the mturalist in any department ofiabour. 



With the junior year fh^- siudies of a strictly biolo- 

 gical character begin. One course includes the elements 

 of comparative zoology, with elementary teaching in 



