April 29, 1909J 



NATURE 



269 



blood vessels of the Tuatara, ot which no account has 

 hitherto been published. The description is believed to 

 be more complete than any hitherto given for any reptile, 

 and a considerable number of vessels are described which 

 have not hitherto been noted in Lacertilia. This com- 

 parative completeness of detail is largely due to the 

 employment of a special method of investigation. By this 

 method the entire contents of the cran'al cavity are fixed 

 and hardened in situ, and are then in e.Kcellent condition 

 either for dissection or for histological purposes. The 

 brain does not occupy nearly the whole of the cranial 

 cavity, there being a very large subdural space (especially 

 above the brain) across which many of the blood vessels 

 run, together with delicate strands of connective tissue 

 which connect the dura mater with the pia. The eyeballs 

 are removed, and an incision is made on each side in the 

 cartilaginous wall which separates the cranial cavity from 

 the orbit. Acetic bichromate of potash (made up accord- 

 ing to the formula given by Bolles Lee) is injected into 

 the cranial cavity through these incisions, and the entire 

 animal, after opening the body cavity, is suspended in a 

 large volume of the same fluid for about five days, ana 

 then graded up to 70 per cent, alcohol. When the cranial 

 cavity is now opened up the cerebral vessels are seen with 

 extraordinary distinctness, although they have not been 

 artificially injected. Further details were made out by 

 means of serial sections, both transverse and longitudinal, 

 and both of the adult and of advanced embryos (Stage S). 

 In most respects the arrangement- of the intracranial blood 

 vessels agrees with that found in the Lacertilia, so far 

 as these have been investigated but there is an important 

 difference in the fact that the posterior cephalic vein leaves 

 the cranial cavity through the foramen jugulare, and not 

 through the foramen magnum, while a slightly more 

 primitive condition is shown in the less complete union 

 of the right and left halves of the basilar arterv. Spheno- 

 don makes some approach to the condition of the Chelonia 

 in this latter respect, but differs conspicuouslv from this 

 group in the fact that the circle of Willis is not com- 

 pleted anteriorly, as well as in the fact that no branch 

 of the posterior cephalic vein leaves the cranial cavitv 

 through the foramen magnum. A very characteristic 

 feature of Sphenodon is the development of large trans- 

 verse sinuses resembling those of the crocodile, but these 

 communicate with the extracranial vascular system in 

 quite a different manner from that described by Rathke 

 in the latter animal. — The graphical determination of 

 Fresnel's integrals: J. H. Shaxby. Fresnel's integrals 

 / cos irx' and / sin i-rrx- can readily be evaluated bv 



applying Simpson's ^rule to the calculated values of 

 cos iirx' and sin ^irx' for a sufficient number of values 

 of X. In the cosine case, the curve 7 = cosi7rx° gives a 

 series of loops, cutting the .i:-axis at x=i, v's, V's^ &c. 

 The areas of these loops, after the first few, are shown 

 to be proportional to the lengths of the bases upon which 

 they stand ; a loop extending from x, to x., has an area 



k{x,-x,), where fc = " =^ o 6366. Thus integration to 

 fairly large values of .v as upper limit may be simply per- 

 formed by adding together (a) the area for the first few 

 loops (with due attention to -t- or — sign) obtained by 

 Simpson's rule; (b) /c2rf. where 2d is the quantit'v 

 obtained by summing (again paying attention to sign) the 

 base lines of the complete loops of higher order than those 

 in (a) ; and (c) the area of the part of a loop bounded by 

 the upper limit, viz. from x,==^/2n—{ to the upper limit 

 of integration x,, where x,' is the greatest odd whole 

 number less than xj. The area (c) is given by the 



expression -^_£— (sin i7ri-,' + i). Similar methods can be 



used for the sine integral. Values of the integrals 

 calculated as above are tabulated, and agree with Gilbert's 

 values to within i part in looo. 



Linnean Society, .April i.— D'. D. H. Scott, F.R.S., 

 president, in the chair. — .Amphipoda Hyperiidea of the 

 Sealark Expedition to the Indian Ocean : A. O. Walker. 

 The Amphipoda Hyperiidea of the Sealark Expedition 

 consist of thirty-five species in twenty-eight genera, none 

 NO. 2061, VOL. 80] 



new to science. Scina borealis, U. O. Sars, has not 

 previously been found in tropical seas. Most of the speci- 

 mens were taken in open tow-nets, so the actual depth 

 at which they occurred is uncertain, but an ovigerous 

 female of Platyscelus armatus (Claus) was taken " off 

 sounding-lead " at 209 fathoms, which shows that this 

 species deposits its ova on the bottom. — iVIarine MoUusca of 

 the Scalarh Expedition ; Dr. J. Cosmo Melvill. The 

 marine MoUusca obtained during the Stanley Gardiner 

 Expedition of 1905-15 arc especially interesting from the 

 standpoint of geographical distribution. Accompanying the 

 catalogue of nearly five hundred species are given tables 

 of comparison with the moUuscan faunas of nine or ten 

 selected " area; " of the Great Indo-Pacific region, one 

 curious result of this investigation being that, whereas 

 many are identical with species found in Polynesia or even 

 Japan, the reverse obtains when comparison is made with 

 the more contiguous fauna of the Persian Gulf and North 

 Arabian Sea. This last has been made the subject of 

 special study during the past fourteen years, and a total 

 of nearly seventeen hundred species chronicled, of which 

 something like five hundred proved new to science. Only 

 one of these new forms {Perisiernia corallina, Melv.) has 

 been found to occur in the Stanley Gardiner collections 

 made in the more southern portions of the same ocean, 

 and comparatively few of the better-known forms are 

 identical. Indeed, the affinities of this collection are, as 

 might be expected, Mauritian. — Land and fresh-water 

 MoUusca of the Seychelles Archipelago : E. R. SyKes. 

 The author gives an account of the land and fresh-water 

 shells collected by Mr. Stanley Gardiner in the Seychelles 

 Islands. Nearly all the known forms are included in the 

 collection, and three species belonging to Ennea (2) and 

 Priodiscus (i) are described as new. A table showing the 

 inter-insular distribution is given, and a list of all known 

 forms. The origin of the fauna is uncertain, but the 

 islands have evidently been for some considerable period 

 separated from the mainland. — .\ blind prawn from the 

 Sea of Galilee, constituting a new genus and species, 

 Typhlocaris galilea : Dr. W. T. Caiman. 



Paris. 

 Academy of Sciences, April 19. — M. Bouchard in the 

 chair. — Examination of the upper layers of calcium and 

 hydrogen in the solar atmosphere, and of the same black 

 filaments in the two layers : H. Deslandres and L. 

 d'Azambuja. The large spectroheliograph at Meudon 

 permits of the examination of the K3 and K, lines, quite 

 pure and free from other light. The black filaments of 

 K, have been compared with the image of Ha. It is 

 concluded that in all previous work the lines obtained for 

 hydrogen represent a mixture of different layers. To 

 obtain the upper layer only, it is necessary to isolate the 

 centre of the black line. — The slowness of the spontaneous 

 transformation of the variety unstable at low temperatures 

 of certain dimorphous bodies : D. Gernez. .An experi- 

 mental study of the equilibrium of yellow and red mercuric 

 iodide and the corresponding varieties of thallous iodide. 

 ■ — The " sense of direction " in bees : Gaston Bonnier. 

 The fact that bees, up to a distance of 3 kilometres, 

 fly in a direct line for the hive, has been explained 

 as due either to the sense of sight or of smell. 

 The author's experiments clearly demonstrate that neither 

 sight nor smell serve for this purpose, and that bees 

 possess a " sense of direction." This sense is not located 

 in the antenns. — The map of south Imerina : the methods 

 of work employed : E. Colin. This map is on the scale 

 of 1/100,000, with contour lines of 50 metres. — Remarks 

 relating to the communication of M. Deslandres : G. E. 

 Hale. In the photographs of Ha it has been found that 

 the relative intensity of the black and brilliant flocculi 

 is determined by the position of the slit relative to the 

 line Ha. If the slit only allows the light from the central 

 portion of the line to fail on the plate, the brilliant flocculi 

 are very intense in the image. If, on the contrary, the 

 image is formed exclusively from the light of the edge 

 of the line, the black flocculi are well seen, but the brilliant 

 flocculi are faint or even invisible. The results are not 

 favourable to the theory of anomalous refraction as the 

 cause of the hydrogen flocculi. — Letter from Dr. J. B. 

 Charcot describing the voyage of the Pourqnoi-pas? 



