2^6 



KNOWLEDGE & SCIENTIFIC NEWS. 



[October, 1905. 



ZOOLOGICAL. 



By R. Lydekker. 

 The Pen-Tailed Tree-Shrew. 



Borneo has hitherto been supposeJ to lo the sole habitat 

 of a very remarkable little animal known as the pen-tailed 

 tree-shrew 1 Ptiloccrcm louei). The creature is a near ally of 

 the tupais, or tree-shrews, of the Indo-Milayan region, but is 

 \ en.- small, and has an exceedingly long cylindrical tail, which, 

 instead of having a fringe of long hairs on opposite sides 

 throughout its length, is furnished merely with a vane of such 

 hairs near the tip. Recently a specimen has been taken in 

 the Selangor district of the Malay Peninsula. Since the long- 

 uosed crocodile known as Sihlegel's gharial (Tomistoma 

 schlei;eli), which was also long supposed to be confined to 

 Borneo, has likewise been discovered in the Malay Peninsula, 

 it is evident that the fauna of these two areas has more in 

 common than was formerly supposed. 



A Giant Pig. 



From the later Tertiary deposits of Nebraska has been 

 recently described the fossilized remains of a gigantic fossil 

 pig. which has been named Diinuhuriis lioll.indi, in honour of 

 the Director of the Carnegie Museum, who recently brought 

 the Diploilocus skeleton to the British Museum. Some idea 

 of the enormous size of this monster will be gathered from the 

 fact that Its skull alone measures nearly a yard in length. 



The "Siruk\i." 



The Mandingos of Liberia, according to Sir H. H.Johnston, 

 " talk a great deal about a striped animal which they call 

 siruku. They recognised a picture of a zebra, and called it 

 siruku, but at the same time described the animal as being 

 extremely ferocious and dangerous to life. As it is impossible 

 to recognise this description as applying to the zebra, I 

 thought from their gestures that they mit^ht mean the leopard; 

 but to the leopard they gave a totally different name — soli. 

 Moreover, they were particular that this animal had stripes. 

 It may be the striped hyxna. .'It the same time, on every 

 occasion when they were shown the pictures of a zebra they 

 declared that this was the creature they called siruku, but that 

 in their countrj- it was ferocious." Even if the siruku be the 

 striped hyxna, it will indicate an animal — possibly a distinct 

 race or species — new to the West African fauna. In India, 

 at any rate, striped hyaenas are skulking cowardly brutes, 

 which never voluntarily attack man ; but this scarcely accords 

 with the character given to the mysterious Liberian animal. 



A Gorilla at the " Zoo." 



The menagfirie in the Regent's Park has received a fine 

 female gorilla, imported from French Congo-land, in company 

 with no less than seventeen young chimpanzees. On arrival 

 at the docks, the gorilla was reported to be in fair health, 

 although sufl'ering from its somewhat restricted quarters on 

 board ship, and since its transference to the Regent's Park has 

 apparently done well. It is the largest specimen imported of 

 late years. 



Bubble-Nesting Fishes. 



Most, if not all. of the fishes allied to the celebrated 

 "climbiog-perch " (.liui'im \caiuicii'.) have the remarkable 

 habit of constructing "nests" or floats of bubbles, in which 

 Ihcir eggs are placed during the period of development. All 

 these fishes arc brilliantly coloured, and, with the exception of 

 one African species, are natives of the Indo-Malayan rivers. 

 Among those definitely known to make floats of this nature 

 arc the gourami (O-phmmniu^ aljux), renowned for the ex- 

 cellence of its flesh, th<' paradise-fish tPolyacniilhiis opcrcularis), 

 and the fighting-fish (Hilla f'li^iuij-], so-called on account of a 

 domesticated breed being kept for fig'nting by the Siamese. 

 Specimens of the two latter have recently been kept in 

 aquariums by an Knglish naturalist, where they have con- 

 structed their bubble-rafts, which arc more or less dome-like 

 in shape. In the case of the paradise- fish, the layers of bubbles, 

 which are blown by the male fish, are gradu.illy increased, and 

 to such an extent that the eggs are raised above the level of 

 the water, in which position they are batched. 



REVIEWS OF BOOKS. 



Spectroscopy. E.C. C. Baly, F.I. C. (Longmans; los.Od.^. — 

 There is probably no subject for which a new English text- 

 book was more required than that of spectroscopy. The 

 advances made have been so considerable that a mere revision 

 of any existing textbook would have been totally insufficient. 

 In Germany a thoroughly satisfactory encyclopa;dic hand- 

 book is being brought out" by Professor Kayser, and this will 

 probably serve as the ultimate book of reference for some 

 time to' come. But this is too elaborate a treatise for the 

 ordinary- student, even when the language in which it is 

 written does not prove an obstacle. The repro.ach that there 

 is no adequate English textbook is roniovcd by the present 

 publication, which forms one of the textbooks of physical 

 science edited by Sir William Ramsay, who is to be congratu- 

 lated on having placed the subject in the hands of one so com- 

 petent to treat it with distinction. The characteristic feature 

 in the treatment is the fulness in the descriptions of experi- 

 mental detail, and of the conditions upon which success in 

 spectroscopic measurements depends. Tho prismatic and 

 difl'raction spectra, and the much derided but now victorious 

 interference methods for the determination of wave-lengths 

 are successively described in great detail. It is a pity that the 

 present edition was not in time to make use of Schuster's 

 recent important demonstration of the erroneoiisness of much 

 that has been written and accepted as gospel on the purity of 

 spectra. The survival of this error vitiates part of what has 

 been written in Chapter .\. The student may here be warned 

 that Schuster's original expression for the purity (p. 317) must 

 be accepted in place of the more elaborate (but erroneous) 

 formula of Wadsworth's ; and consequently he should alter 

 the formulye in this chapter accordingly. 



Sixty pages are devoted to the means of producing the 

 luminous sources of spectra ; and twenty-four to the various 

 kinds producible. Chapter XV. consists of an elaborate and 

 very complete account of the series of lines in spectra and 

 the different formula; which have been devised to represent 

 them. We miss, though, any reference to N.agaoka's theoretic 

 discussion of the reason of the existence of these series. 

 There is a wide field here in which much has yet to be done; 

 and the full and clear account which Mr. Baly gives will be a 

 very welcome summary of experimental facts to those who 

 are interested in the matter. An outline of present experi- 

 mental knowledge of the Zeeman effect forms Chapter XW. 

 It must be understood that the treatment throughout is limited 

 to simple mathematics. It is, of course, impossible to put 

 everything under one roof; and copious references to original 

 sources guide the reader who wishes for fuller information. 

 There are very few inaccuracies. The first account of the 

 ideal grating was given by Schwerd not by Rayleigh ; and 

 Newton ilid use a slit ; though it is quite common to find it 

 denied of him. In biaxal crystals iieillier ray is, in general, 

 ordinary; the definition of optic axis on p. 96 is imperfect. 

 The logic on p. 155 in connection with resolving power is of 

 the circular type. These, however, are minor matters ; and 

 they do not appreciably detract from the great value of this 

 important work. 



Structural and Field Geology, by James f jcikic, LL.D., &c., 

 author of " The Great Ice Age," &c. (I'^dinburgh : Oliver and 

 Boyd. London : Giirney and Jackson. I'p. xx. and 435. 

 Price I2S. 6d. net. With Oi full-page plates, and 142 illustra- 

 trations in the text). — It is a pleasure to call attention to this 

 excellent mantial, in which Dr. Gcikie has traversed the whole 

 field of the geological world in a m.anner which must cause it 

 to be of the utmost value, both to the purely scientific geologist 

 and to those eng.aged in professions in which a general know- 

 ledge of the principles of geology is a necessity. While fur- 

 nishing excellent reading for the general public interested in 

 the subject, it will undoubtedly be useful as a manual to guide 

 the student in the acquisition of exact and accurate knowledge. 

 It is a work, loo, which should be in the hands of all engineers 

 who have in the slightest way work to do in which a knowledge 

 of the constituents of the crust of the earth is neces.sary. The 

 illustrations are excellent, and in the absence of actual speci- 

 mens of the minerals and rocks referred to in the text, nothing 

 could be better for purposes of the student. As ins'ances, we 

 may mention the section of an agate, on Plate I. ; tabular 



