March 1 2i, 1879] 



NATURE 



451 



*' Observations on the Physiology of the Nervous System i 

 of the Crayfish {Astaais fluviatUts)" by James Ward, M.A., | 

 Fellow of Trinity College, Cambridge. Presented by Michael 

 Foster, M.D., F.R.S., Praelectorof Trinity Collie, Cambridge. 



The experiment?, of which this paper gave a brief account, 

 consisted mainly in severing (i) one or (2) both of the supra- 

 cesophageal commissures, (3) both the sub-oesophageal commis- 

 snres, or (4) in dividing the supra-cesophageal ganglia longitudi- 

 nally. From these experiments it was inferred : — 



(a) That there is no decussation of the longitudinal fibres in 

 the nervous system of the crayfish. 



(b) That oa the presence of the srapra-oesophageal ganglion 

 depend (i) the spontaneous activity of the animal as a whole, or 

 what might be called its volitional activity ; (2) the power to 

 inhibit the aimless and wasteful mechanical activity of the lower 

 centres ; (3) the power to maintain equilibrium ; and (4) the use 

 of the abdomen in swimming. 



(r) That the snb-oesophageal ganglion is the centre for co- 

 ordinating (i) the locomotive, and (2) the feeding movements, 

 and (3) for a peculiar rhythmic swing of the limbs seen as soon 

 as the supra-cesophageal ganglia are removed, and (4) is the 

 source of a considerable amount of motor energy, 



{d) That there is much less solidarity, a much less perfect 

 consensus, among the nervous centres in the crayfish than in 

 animals higher in the scale. The brainless frog, e.^., is motion- 

 less, except when stimulated, and even then does nothing to 

 suggest that its members have a life on their own account ; 

 whereas the limbs of a crayfish deprived of its first two ganglia, 

 are almost incessantly preening, and when feeding movements 

 are started, the chelate legs rob, and play at cross purposes with, 

 each other as well as four distinct individuals could do. 

 je (e) That some stimulus from other centres is more or less 

 necessary to the activity of any given centre. 



(/) The "natural" discharge of a ganglionic centre (not 

 exhibiting "volition") appears to be of a rhythmic kind; the 

 rhythmic movements becoming converted into varied movements 

 by temporary augmentation or inhibition. 



Zoological Society, March 4. — Prof. W. H. Flower, 

 F.R.S., president, in the chair. — Mr. Sclater exhibited and 

 made remarks on examples of two rare Fruit Pigeons, of the 

 genus Carpophaga. — Mr. L. M. D'Albertis exhibited some new 

 and rare birds, obtained during his recent expedition up the Fly 

 River, New Guinea. — Prof. Newton exhibited, on behalf of Mr. 

 J. Robinson, of Trinity Hall, Cambridge, a specimen of Sylz-ia 

 nisoria, believed to have been killed at Cambridge many years 

 aco. — A commvmication was read from Mr. L. Taczanowski con- 

 taining a list of the birds collected by Messrs. Stokmann and 

 Jelski, in Northern Peru in 1878. Fifty-six species were 

 enumerated, several of which were new to science. — Mr. R. 

 Bowdler Sharpe, F.Z.S., read some notes on birds obtained on 

 Kina-Balu Mountain, in North-Westem Borneo, by the collectors 

 of Mr. Treacher, amongst which were several species new to 

 science. — Mr. F. JeflFrey Bell read the first portion of some 

 observations on the characters of the Echinoidea. The present 

 paper contained remarks on the species of the genus Brissits and 

 on the allied forms Aleoma and Metalia. — A communication was 

 read from the late Mr. F. Smith, F.Z.S., containing the descrip- 

 tions of new species of Hymenoptera from Central America. — A 

 communication was read from Mr. VV. A. Forbes, F.Z.S., con- 

 taining a synopsis of the Meliphagine genus Myzomda, to which 

 was also added the descriptions of two new species. — A com- 

 munication was read from the Rev. O. P. Cambridge, containing 

 descriptions of some new and little known species of Araneidea, 

 principally belonging to the genus Gasteracantha. 



Chemical Society, March 6. — Dr. Gladstone, president, in 

 the chair. — The following papers were read ; — On tfie quantita- 

 tive blowpipe assay of mercury, by G. Attwood. The method 

 consists in distilling the compounds either alone or mixed with 

 litharge or with oxalate of potash and cyanide of potassium in 

 ingeniously contrived retorts of glass or steel, the whole appa- 

 ratus being three to four inches long, collecting the mercury in 

 water, and weighing it when dry. — On some points in the analy- 

 sis of combustible gases and in the construction of apparatus, by 

 J. W. Thomas. The author has succeeded in exploding marsh- 

 gas, &c., with almost theoretical quantities of oxygen, by iLsing 

 a diminished tension, about 160 mm. As less oxygen is thus 

 required, the author has shortened the eudiometer tube to 

 500 mm. and thereby increased the delicacy of the apparatus ; he 

 has also reintroduced a steel tap, of, however, perfect tightness, 

 and has in several points perfected and simplified the ordinary 



Frankland's and McLeod's apparatus. The steel face plates 

 connecting the laboraltory and measuring-tubes have also been 

 aband<med. — On the action of isomorphotis salts in exciting the 

 crystallisation of super- saturated solutions of each other, and 

 some experiments on super-sattu-ated solutions of mixed salts, by 

 J. M. Thomson. The author finds that a crys'al to act as a nucleus 

 must be not only isomorphous, but chemically similar, as to 

 the water of crystallisation and to the substance in solution. In- 

 teresting results were obtained by introducing a nucleus into a 

 super-saturated solution of two non-isomorphous bodies ; under 

 certain conditions a separation of these two bodies could be 

 effected. — On the isomeric dinaphthyls, by Watson Smith. The 

 author has determined the vapour densities of the dinaphthyls by 

 means of V. Meyer's new apparatus, and gives in his paper the 

 results of the reaction of carbon tetrachloride, chloroform, &c., 

 on naphthalene. 



Geological Society, February 21. — Henry Clifton Sorby, 

 F. R.S., president, in the chair. — George Bond, Francis Gaskell, 

 and George Henry Hollingworth, were elected Fellows of the 

 Society. — The following communications were read : — A copy 

 of a letter from the late Acting-Governor of the Falkland Islands, 

 relating to the overflow of a peatbog near Port Stanley, in East 

 Falkland. Communicated by H.M. Secretary of State for the 

 Colonies. — Note on Poikilopleuron bucklandi, of Eudes Deslong- 

 champs (ph-e), identifying it with Megalosaurus bucklandi, by 

 J. W. Hulke, F.R.S. — Note on a femur and a humerus of a 

 small mammal from the Stonesfield slate, by H. G. Seeley, 

 F.L.S., F.G.S., Professor of Geography in King's College, 

 London. — A review of the British carboniferous Fenistellidse, 

 by G. W. Shmbsole, F.G.S. 



Anthropological Institute, February 25. — Mr. John E^-ans, 

 D.C.L., F.R.S. , vice-president in the chair. — A paper by Mr. 

 C. Staniland Wake, on the primitive human family, was read 

 by the Director, The author endeavoured to combat some of 

 the views usually associated with the name of Mr. McLennan. 

 — Mr. E, W, Brabrook, F,S.A,, read a paper entitled " Notes 

 on the Colour of the Skin, Hair, and Eyes." The paper accom- 

 panied an exhibition of the "Echelle de Conleurs," published 

 by the Societe Stenochromique of Paris. The accurate deter- 

 mination of the colours of the skin, hair, and tyes, is a matter 

 of great interest to anthropologists, and the author considered 

 that thouyh the object of the publication of this scale of colours 

 was not exclusively anthropological, yet its value to anthropolo- 

 gists would be very great. Forty-two colours are specialised, of 

 each of which there are about twenty shades. 



Victoria (Philosophical) Institute, February 3. — Prof. 

 McK. Hughes, F.R.S., delivered a lecture upon the antiquity of 

 man, in which he analysed the nature of the evidence brought 

 forward by others. 



Cambridge 



Philosophical Society, February 24. — Prof. Liveing, pre- 

 sident, in the chair. — Prof. Cayley gave an acount of an 

 investigation which he had been led to, relating to what he calls 

 the "Newton-Fourier Imaginary Problem." The Newtonian 

 process of approximation to the root of a numerical equation 

 f{u) — o, consists in deriving fi-om an assumed approximate 



' '" which should be a closer 



root f, a new value f ^ = f - 



/'(I) 



approximation to the root sought ifor ; taking the coefficients of 

 f{n) to be real, and also the root sought for, and the assumed 

 value I, to be each of them real, Fourier investigated the 

 conditions under which |i is in fact a closer approximation. 

 But the question may be looked at in a more general 

 manner ; | may be any real or imaginary value, and we have to 



inquire in what cases the series of derived values |j = | - i- — ^ 



/•(f)' 

 converge to a root, real or ima^ary. 



of the equation/ («) = o. Representing as u^ual the imaginary 

 value I, = jr -h iy, by means of the point whose co-ordinates 

 are x, y, and in like manner f j, — x^ + ty^, &c. ; then we have 

 a problem relating to an infinite plane ; the roots of the equation 

 are represented by points A, B, C, . . . ; the value | is repre- 

 sented by an arbitrary point P; and from this by a determinate 

 gcrometrical construction we obtain the point /*,, and thence in 

 like manner the points P^ P^ . . . which represent the values 

 in l-2» €3 • • • respectively. And the problem is to divide the 

 plane into r^ons, such that starting with a point /j anywhere 



