March. 1902.] 



KNOWLEDGE, 



63 



Jupiter, Satellite I. . 

 Jupiter, Satellite II. 

 Jupiter, Satellite III. 

 Jupiter, Satellite IV. 

 Saturn, equatorial 



Miles. 

 2,452 

 2,045 

 3, .558 

 3,345 

 76,470 



Saturn, polar ... 

 Saturn, Satellite Titnii 

 Uranus, equatorial 

 Uranus, polar .. 

 Xeptune 



MUes. 

 69,780 



2,720 

 35,820 

 33,021 

 32,900 



A vougU attempt to deterniino tln' total liu^ht of the 

 stars by direct observation has been made by Prof. Simon 

 Newcomb, who is inclined to regard this quantity as 

 among the most important fundamental constants of 

 astrophysics. The methods of observation were extremely 

 simple, consisting chietiy of I'ompariug sky illumination 

 with the image of a star of known magnitude dift'used 

 into a disc by a suitable concave lens, and reduced liy 

 means of dark glasses when necessary. It was fi>und that 

 the total light of all the stars is about eqiial to that of 

 (500 stars of zero magnitude, with a probable error of one- 

 fourth of the whole amount. A positive correction, 

 however, is more jirobable than a negative one, and the 

 number may possibly be greater than 800. From statistics 

 relating to the numbers of stars and nebula}, it will be 

 remembered that Mr. Gore concluded that the total light 

 was equal to 589 stars of zero magnitude. 



We learn from Bulletin No. 1-t of the Lick Observatory 

 that two oval nebulous rings surrounding Nova Persei 

 were photographed as far back as March 29th, 1901, 

 although the plate was only exposed for ten minutes as 

 couipared with the ten hours which now appears to be 

 necessary. The rings were then quite small, but it is 

 considered that the later rings may be regarded as having 

 been produced by expansion outwards from the Nova. 

 Assuming the identity of the earlier and later forms, the 

 daily radial rate of motion is found to be 2"'62 in the 

 south-west quadrant, and 3"00 towards the north. At 

 this rate the nebulous matter would have been coincident 

 with the Nova on February 16th or 17tb, and some of it 

 might be expected to reach the solar system in about 

 2.50 years if the same rate of expansion is maintained, 

 supposing that there is actual translation of the nebulous 

 material. — A. F. 



BoTANicAi,. — The question of the systematic position of 

 the Nymphscacece— whether they should be included in 

 the Dicotyledons or the Monocotyledons — has already been 

 discussed by several botanists. It is brought forward 

 again in a paper by Mr. H. L. Lyon, which api)ears in the 

 Minnenota Botanical Studies, Series 2, Part V., where he 

 records his "Observations on the Embryogeny of Nelumbo." 

 In Bcntham and Hooker's system the Nymphteaceae are 

 placed in the Kanales, between the Berberidacea? and the 

 Sarraceniaceaj. Mr. Lyon shows that Net umbo, both in its 

 anatomy ami embryogeny, conforms to the type of the 

 iloBocotyledons ; that there is only one cotyledon, the 

 two fleshy lobes of the embryo, described by some liotanists 

 as cotyledons, really arise through the bifurcation of the 

 originally single cotyledon ; and finally, that the order to 

 which it belongs should be included in the Monocotyledons, 

 ill the series HelobiiB, which includes Potamogetoii, Alisma, 

 Biitomus, &c. Referring to the subject in the January 

 number of the American Naturalist, Prof. D. H. Campbell 

 points out that the Lesser Celandine {Ranunculus Ficaria) 

 has only one cotyledon, and that the Ranunculacete, 

 resembling in their flowers those of the Alismales, are 

 amongst the anomalous Dicotyledons. 



The origin of the stipules in Liriodemlron, represented 

 by the well-known tulip-tree of our gardens, is the subject 

 of a paper in the Bulletin of the Torrey Botanical Club, of 

 September, 1901, by Mr. E. W. Berry. The writer has 

 examined a great number of leaves of L. tuUjiif, ni, and 

 taking into account the l^af of a fossil species recently 



described l)y Dr. A. Hollick, and the leaves of allied 

 genera of Magnoliacete, supports Dr. Hollick's opinion 

 that "the large fugacious stipules of our living tulip-tree 

 might represent former leaf-lobes, which, becoming 

 separated, formed basilar lobes, then winged petioles, and 

 finally the modem stipules." — S. A. S. 



Zoological. — On the evening of Friday, January 7th, 

 Professor E. Ray Lankester, Director of the Natural 

 History Branch of the British Museum, delivered at the 

 Royal Institution a lecture on the okapi, illustratc<l by 

 a life-sized coloured sketch of that remarkable mainmai. 

 The relationship of the okapi to the giraffe and the extinct 

 Kelladotherinm and its allies was fidly discussed. 



Allusion ha.s been already made in these columns to the 

 splitting-up of the puma into a number of so-called 

 species. Recently Mr. E. A. Mearns [Proc. Washington 

 Academy, Vol. XIV., p. 137) has followed the same course 

 in the case of the jaguar. Undoubtedly different local 

 forms and jihases of both the jaguar and the jnima do 

 exist, and, if it be thought desirable, there can be no 

 objection to indicating them by sub-specific or varietal 

 names. When, however, it comes to calling them species 

 the case assumes a very different aspect, for we are then in 

 danger of losing sight of the all-important fact that these 

 two types of cat range over a very large portion of the 

 American continent (the puma much farther than the 

 jaguar). In return for this loss, we gain — nothing, if 

 not worse than nothing. It is a case of Losing sight of 

 the wood for the trees, and the sooner this practice of 

 excessive species-making on the part of specialists is 

 discouraged, the better it will be for the true interests of 

 natural history. No advantage whatever can be urged in 

 favour of the practice, while there is much that can be 

 said against it. 



Had space permitted, we should have called attention at 

 an earlier date to a very interesting paper by Miss D. 

 Bate on the mammals discovered by herself in a Give in 

 the Wye Valley near the Foi-est of Dean, which appeared 

 in the Geological Magazine for last year. The special 

 interest councrtcd with these remains is that they are 

 chieflv those of bats, insectivores, and rodents, and that 

 many of the latter belong to Arctic and Alpine types at 

 present unknown in Britain. The species include the 

 Norwegian and the banded lemming, the pica, the northern 

 vole, the Alpine vole, and the Continental field-vole, as 

 well as several still existing in Britain. Hitherto, almost 

 the only evidence of the former presence in Britain of the 

 Arctic and the Alpine vole has been afforded by remains 

 from Somersetshire and Wiltshire. 



The theory that the horns of the big-horn wild sheep 

 (Ovis canadensis) act the part of megaphones in conveying 

 sound to the ears of their owners, which was discussed at 

 a recent meeting of the Linnean Society, has formed the 

 subject of correspondence in the columns of The Field. 

 One observer writes very strongly against the likelihood 

 of the theory being true, and some of his arguments will 

 be found very difficult to controvert. It is a pity, however, 

 that he uses the term helij; when he means pinna, or 

 conch. 



In a paper on a collection of mammals from Shendi, on 

 the Upper Nile, published in the December issue of 

 Novitates Zooloyicx, Mr. W. E. De Winton names a spiny 

 mouse Acomys u-itherhyi, in honour of Mr. H. F. Witherby, 

 by whom the type specimen was collected near Khartum. 

 A new species of gerbil (Gerbillus watersi) is likewise 

 named in the same communication. 



With the exception of a few forms which entered North 

 America during the Pliocene and Pleistocene epochs, the 



