232 



KNOWLEDGE. 



[OcTorKR 1. IfiOr. 



of retlectors, is eriipliasi/.oJ of prosurviug die objective in 

 dry pure air. In humid climates a line lihn of moisture 

 deposits or exudes from tlie interior surface of the crown 

 lens, and on this moisture a minute thread-like fungus 

 spreads and decomposes the crown glass, resulting in the 

 ultimate deterioration of the lens. The simple preventa- 

 tive is suggested of placing within the dew-cap some 

 thicknesses of flannel, left toasting before the fire until 

 perfectly warm and dry, after the observations for the 

 night are finished. C'uriously, this iilm does not invade the 

 flint surface. The tarnish which appears on this glass in 

 reality increases very greatly the transparency of the 

 objective. Whereas a thin plate of dense flint glass will, 

 when freshly polished, reflect back from its two surfaces 

 about eleven per cent, of the light falling upon it, and 

 transmit eighty-nine per cent. ; the same plate, when 

 tarnished to a sort of dull grey-brown or blue (as viewed 

 by reflection), will reflect back only about five per cent., 

 and transmit ninety- five per cent. 



Souihifn Starx : a Guide to the Constellations visible in the 

 SoKtheni llimis/ihfi-e. By M. A. Orr. With a Preface by 

 John Tebbutt, F.R.A.S. The Rev. James Gall's " Easy 

 Guide to the Constellations" has been the first primer 

 which has taught a great number of northern observers 

 their stellar alphabet, and on the acquaintance with the 

 forms of the constellations and the names of the stars to 

 which they have been thus introduced, has followed the 

 rise of a love for astronomy which has in many cases borne 

 rich fruit. It is, therefore, with especial pleasure that we 

 welcome Miss Orr's modest little book. For the southern 

 heavens present a rich harvest which there have been very 

 few labourers to reap, and hitherto it has seemed much 

 more difficult to arouse a real interest in astronomy in 

 southern latitudes than here in Europe. We trust that 

 Miss Orr's book is at once an indication of an awakening 

 interest, and that it will greatly foster it. It should do so, 

 for the work is most clearly written, and, following on the 

 weU-chosen lines of Mr. Gall's book, is in every way a 

 thoroughly worthy companion and supplement to it. With 

 Miss Orr's neat little maps and lucid descriptions ready to 

 his hand in so convenient a form, the South African or 

 Australian will now be without excuse who looks upon the 

 glories of his southern skies as a mere confused crowd of 

 unknown and nameless stars. It should be added that 

 the thirty maps are not confined wholly to the southern 

 hemisphere, as six of them form a complete miniature star 

 atlas for the entire heavens. 



In the Journal of Botanij for August there is a very in- 

 structive paper by T. Kirk, F.L.S., on "The Displacement 

 of Species in New Zealand," showing the effects of introduced 

 animals and plants upon the old fauna and flora of that 

 island. Darwin's theory of the " survival of the fittest" 

 receives further corroboration from the many interesting 

 facts recorded in this paper. The author says : " . . . . the 

 invading army of plants has brought in its train a still 



more dangerous host of animals In the animal 



kingdom the invaders whose agency is most dreaded are 

 members of the Invertebrata : the mussel scale, the black 

 scale, and many others, together wit'n numerous species of 

 plant lice, will occur to you as belonging to lowly developed 

 forms of Insecta. Higher in the scale are thd JJessian fly, 

 wireworm, turnip fly, and others, while numerous species 

 of earthworms, molluscs, birds, and even mammals, affect 

 alike both fauna and flora." Again, showing how plants 

 adapt themselves to their environment, the author reports 

 that " out of one hundred and three species of plants 

 recently introduced with b illast from Bue los Ayres, eighty- 

 six are already naturalized." In the same journal 



(pp. :M0-3.")1) there are some new spojies of marine algte, 

 from Natal, described by E. M. Holmes, F.L.S. 



In the Aiiii'rifdii Naiunilist for .luly there is a paper on 

 " The Classification of Diatoms " (Ihicillaridceir), by C. J. 

 I'llmoro, ill which the author discusses the various systfims 

 of classification employed by Kirchner, Kuetzing, Paul 

 Petit, Van Heurck, Murray, and others. In the classi- 

 fication which this author adopts- that of Paul Petit, aa 

 approaching most nearly a natural one several of our 

 most cherished species {'!) are shown to be mere varieties 

 of the Naficula iridis (Ehr.). The author also temperately 

 discusses the reasons of the imperfection of the geologic 

 records of the early history of these Diatoms. 



Entomologists who are interested in the flower-visiting 

 habits of insects will fiud an interesting paper upon " The 

 ]5ees of the Genus Perdita " in the Pnn-irdinns of the 

 Acadruii/ of Xotunil Sciimrs, Part I., 1896 ; and though we 

 do not believe that the number of species will be found to 

 be correct on further examination (our author describes 

 seventy species, of which he believes fifty-five to be new), 

 still the results given in this excellent paper are well 

 worthy of a more extended notice than can be given in 

 these columns. The name of the author is T. D. A. 

 Cockerell. 



Evolutionists, and students of the history of the 

 Mammalia, will do well to make themselves acquainted 

 with one of the latest books upon the subject, viz., " The 

 Primary Factors of Organic Evolution," by Prof. E. 1). 

 Cope, Pennsylvania. The splendid memoirs written by 

 this distinguished palaontologist rival those of our own 

 country upon these subjects. Those who have had 

 occasion to refer to the works of this author know how 

 thoroughly up to date the information is. In the present 

 work the author gives his reasons for disagreeing with 

 the classification adopted by Dr. Amenghino of a portion 

 of the group of Ungulata. " Amenghino placed the 

 group " (called by Dr. Amenghino " Litopterna ") " under 

 the Perissodactyla, but the tarsus and carpus are of a 

 totally dift'erent character." The author further describes 

 the difl'erent characters of the feet, and the dentition of 

 these animals — found by Dr. Amenghino in the Cenozoic 

 formations of Argentina — which leads him to indicate the 

 origin of these species from a different order of the Condy- 

 larthra than of that adopted by Dr. Amenghino. If we 

 remember rightly, Mr. R. Lydekker visited the museums 

 of Buenos Ayres and La Plata to help revise the work of 

 the Argentina palaeontologists ; but, as far as can be seen, 

 with no success as to the classification of these animals. 

 Prof. Cope writes with all the fire of Weismann in defence 

 of the transmission of the germ plasma and of progressive 

 evolution. 



RUNES AND OGHAMS. 



By Gertrude Burford Rawlings. 



Euues ot war kuow tliou 



If great thou wilt be ! 



Cut them on hilt of hardened sword, 



Some on the brand's back, 



Some on its shining side, 



Twice name Tyr therein. 



Sea-runes good at need, 



Learnt for ship's savinj?, [horse; 



For the good health of the swimming 



On the stern cut them, 



Cut them on the rudder-blade . . , 



Word-runes learn well 

 If thou wilt that no man [gavest 

 Pay back grief for the grief thou 

 Wind thou these, 

 ''Veave thou these, 

 Cast thou these all about thee, 

 At the Thing, 

 Where folk throng, 

 Uuto the full doom faring. 

 Thought-runes shalt thou deal with 

 If thou wilt be of all men 

 Fiirest-souled wiglit, and wisest. 

 — Bry-ahild's Song ; " VoJsumja Sa-ja." 



ALTHOUGH it is at present an exceedingly doubtful 

 point as to whether those strange old-world 

 characters known to antiquaries as "runes" and 

 " oghams " respectively, are or are not connected 

 with each other either collaterally or lineally, 

 they form a most interesting subject of speculation. There 



