134 



KNOWLEDGE A: SCIENTIFIC NEWS. 



IJuNli, 1905. 



The apparatus employed by Professors Nichols and Hull 

 consists of two light mirrors mounted on a horizontal capillary 

 glass tube which is suspended at its middle by a quartz fibre 

 about an inch long. \\'hen a strong light (from the sun or 

 electric arc) is focussed on one of the mirrors, it drives it 

 back and thereby twists the fibre. The angle through which 

 the suspended mirrors turn can be observed by reflecting a 

 second beam of light from another mirror mounted on the axis 

 of rotation. 



The chief beauty of the e.xperiraent consisted in showing 

 that for a particular pressure of the air the disturbance 

 arising from it is almost zero ; and most of their measure- 

 ments were therefore made at this pressure. Bat even at 

 other pressures the fint motion of the siispiiuial iv/jits is ahiuiys 

 due to the radiation. The reason of this is that the pressure 

 due to the radiation acts instantaneously ; but the air effect 

 depends upon the vanes gradually warming up, so that the 

 action arising therefrom is always delayed. 



The results of Nichols' and Hull's experiments are in satis- 

 factorj' agreement with Maxwell's theory. 



ZOOLOGICAL. 



By R. Lydekker. 

 The Pelatgic Lancelet, 



The border-land between vertebrates and invertebrates 

 naturally possesses an interest surpassinji that which attaches 

 to what we call ordinary members of the animal kingdom ; 

 that is to say, to those which conform more or less completely 

 to a normal type and possess a host of near relations. One 

 of the most remarkable of these inhabitants of the border- 

 land is the tiny translucent creature of little more than an 

 inch in length not uncommon on sandy shores in the Mediter- 

 ranean, to which our great ichthyologist gave the appropriate 

 designation of lancelet. Long considered a fish, it is now 

 regarded as more nearly related to the sea-squirts, or asci- 

 dians ; and with the latter is ranked as chordate rather than 

 a vertebrate animal. .Among its many peculiarities is the 

 absence of any distinct head, the position of the mouth on the 

 under surface of the anterior end of the body, and the ring of 

 tentacles with which the opening of the mouth is surrounded. 

 Many kinds of lancelets are now known, all save one of 

 which conform more or less closely to the general type. The 

 exception is a species long represented only by a single 

 specimen taken during the scientific cruise of H.M.S. 

 Challenger in the open s(ra. Of this species a number of 

 specimens have recently been described, and these serve to 

 show that it is a very distinct type indeed, characterised not 

 only by its pelagic habitat, but by the position of the mouth 

 on one side of the body, the absence of the ring of tentacles 

 fringing the mouth-opening, and several other equally im- 

 portant structural pecul aritics. 



Luminous 2»hrimps. 



The Prince of .Monaco, whose aetive interest in the fauna 

 of the deep sea is well known, is reported to have lately dis- 

 covered luminous shrimps, which live at a great depth where 

 all, of course, is dark. When placed in a(|uariiims these 

 crustaceans soon, however, loo?c their luminous properties. 

 Probably most, if not all, abyssal organisms arc luminifcrous, 

 or phosphorescent, some giving forth light from the general 

 surface of the body, and others from special organs. 



The Cak.rnegie DinosaLur. 



On May 12th. [...rJ .\vel,iry. on I. half of the TrusteeF, 

 formally received from Mr. Carnegie the gift of a model of 

 the skeleton of the great dliiosaurian reptile Diplodocua car- 

 nei^ii. which has been recntly set up in the reptile gallery of 

 the Natural Hislorv Mnsenm under the imine;dialc superin- 

 tendence of Ur. Holland, Director of the Carnegie Museum 

 at Pittsburg. The skeleton, as now set up, gives a far better 



idea of the enormous proportions attained by these gigantic 

 reptiles than was ever previously possible in this country, 

 even with the aid of the imperfect skeleton in the Geological 

 Department of the Museum collected by Mr. A. N. Leeds, 

 near Peterborough. The skeletons from which the model in 

 the Museum were constructed were obtained from the Upper 

 Jurassic formation of Colorado and Wyoming; from which 

 horizon the late Prof. Marsh long since secured the remains 

 of the typical species to which he gave the name DiploJocus 

 longiis. .Vs set up, the skeleton measures about 75 feet in 

 length, but were the skull and vertebr;c arranged in a straight 

 line the length would be some ten feet more. At the shoulder 

 the creature stands about 14 feet in height. The skeleton 

 is mounted with the head and neck stretched out nearly in 

 the line of the back ; but we may be permitted to doubt whether 

 this was the normal attitude of the reptile in life, especially 

 in view of the fact that the nostrils opened on the top of the 

 head, which suggests an amphibious existence. Diplodocus 

 differs from its relatives by its feeble teeth, which resemble 

 lead-pencils, and are confined to the front of the jaws. Such 

 a feeble dentition suggests that the creature procured its food 

 in the water. By his numificent gift Mr. Carnegie has laid all 

 in this country who arc interested iu natural history under a 

 deep obligation. 



Fossil Marmot Burro>vs. 



Some years ago .American geologists described certain large 

 spirals of hard stone met with in rocks of soft structure under 

 the name of " devil's corkscrews," or, more scientifically, as 

 JhTiiKincluiix. How the.se strange and gigantic spirals were 

 formed h.id long been a mystery, although some naturalists 

 suggested that they were of vegetable origin. Dr. Holland 

 has explained that they are really the solidified burrows of a 

 marmot allied to the existing " prairie-dog " (Cynoiiiys liiduvi- 

 cianiis). Hence, we presume, Damonohelix becomes the 

 generic name of a mammal. 



The Ma.n-like Apes. 



Naturalists will proli.ihly be divided in opinion as to the 

 value of Mr. Rothschild's paper on anthropoid apes in the .April 

 number of the Zoological Society's Proceedings, and some 

 of them, at any rale, will not endorse all his views with 

 regard to the nomenclature. One of the most interesling 

 observations records the fact that two different types of orang- 

 utans are to be met in the same districts, in one of which the 

 faces of the old males are expanded into a kind of warming- 

 pan shape, while in the other they are of more normal con- 

 tour. Mr. Rothschild explains this by " dimorphism," and 

 regards both types as belonging to a single f pecics, and even 

 to the same race. Amorg chinipanzis two distinct lyptsare 

 likewise stated to inhabit the same districts, but lure the 

 author regards the two forms as separate species, each of 

 which may have several local races. Whether this explana- 

 tion of a very curious puzzle will be generally accep:ed 

 remains to be seen. 



Pa-pers R^ead. 



.At the meeting of the Zoological Society on April iStli Dr. 

 A. Smith Woodward read a paper on the skeleton of Cetio- 

 sauriis (or, as being derived, k^T.7, Ceteosaurtis) o.xoniensis 

 from the Oxford clay of Peterborough ; while the Secretary 

 described a young Nigerian giratl'e (diraffd camclopardalis 

 peralta). As mentioned in our last issue, Mr. A. E. Shipley 

 described various infernal parasites obtained in the Society's 

 Gardens and elsewhere, and Mr. R. H. Burns discutsed the 

 anatomy of the leathery turtle. Messrs. Thomas and Schwann 

 gave an accoimt of a colUxlion of South -African quadrupeds, 

 Mr. G. A. Honlenger described a new \'nnnan newt, Dr. I". 

 Lonnberg noticed hjbrid I'mopean han^s, and Mr. .A. L. 

 Butler referred fothegiant eland of the Bihr el-flhazal. The 

 papers read on May 2nd included one, by Prof. Minehin, on 

 sponges of the group I.cticoselenia, &c., a second, by Mr. 

 Bf-ddard, on the anatomy of the ferret-badger, and a third, 

 by Mr. W. P. Pycraft. oii th«! osteology and aftinilies cf the 

 birds of tjie f.imily KniyUcnidcc. 



