November 8, 1S94J 



NATURE 



to Dr. Hinde, who found those from Carzantic Quarry, near 

 Launceston, full of radiolarian casts, withoneinstanceof structure. 

 Further investigations were being made in this diiection by Mr. 

 Ussher and himself. In conclusion, he drew attention to the 

 unwise practice of taking away shingle from beaches faster than 

 it was being reproduced by nature. 



In connection with the controversy over preformation and 

 epigenesis which at present agitates the biological world, we 

 may draw the attention of our readers to a series of articles 

 contributed by Wilhelm Haacke to the Nalnnvissenschaflliche 

 Wochenschrift ['&A. i.\. Nos. 32-3S, Aug. and Sept. 1894), under 

 the title " Schopfung und Wesen der Organismenform." The 

 writer passes under review the various theories of the origin and 

 development of organisms which are associated with the names 

 of Albrecht von Haller, Wolff, Blumenbach, Goethe, Lamarck, 

 St. Hilaire, D.irwin, Weismann, Roux and other biologists, and 

 criticises them from a standpoint not far removed from that of 

 Oscar Hertwig. The synthetic views of the author do not give 

 one the impression of finality, but, as a historical rhumd of the 

 oscillations and tendencies of thought upon some fundamental 

 problems in biology. Dr. Haacke's essay is distinctly interesting. 



The importance, both from economic and from scientific 

 points of view, of a thorough knowledge of the floating 

 fauna and flora round our coasts is so generally recognised, 

 that our readers will be interested in a recent article which, 

 in concise form, furnishes a number of valuable data upon 

 this subject, and must considerably facilitate the further 

 prosecution of similar researches. The article forms part of a 

 report contiibuled by Mr. \V. Garstang to the current number 

 of the JourtHil of the Marine Biological Associatioti, in which 

 the author gives a record of his observations upon the fauna 

 during 1S93-94, and upon the breeding seasons of marine 

 animals at Plymouth, and also submits an attempt to construct 

 a calendar of the changes observable in the floating fauna from 

 month to mojith in the same locality. Dcr Aiifang ist das 

 Sc/nver, and marine biologists familiar with the seeming fickle- 

 ness of marine phenomena know well the powers of discrimina- 

 tion and the experience necessary for the production of 

 accurately generalised information under this head. It is most 

 satisfactory, therefore, that the valuable work upon our north- 

 eastern fauna, which Prof. M'Into;h has conducted for many 

 years past at St. Andrews, should be now supplemented I'y 

 the obiervations of another competent naturalist on our south- 

 western shores. If, as we hope, arrangements can before long 

 be made for carrying on continuous observations at the young, 

 but promising, station at Port Erin, and on the west coasts of 

 Ireland and Scotland, we shall in good time be equipped wiih 

 data of the most valuable kind for determining many problems 

 connected with the natural history of our migratory and other 

 fishes. 



The second of the Tufis College StuJies embodies the 

 results of an investigation of the development of the lungs 

 of Spiders {AgeU-iia invia and Theiidium tepidaiiorum) by 

 Orville L. Simmons. The author's interpretations difl'er ei.^ 

 tirely from those of Jaworowski, already noticed in our columns 

 (October 25, p. 621). He finds that the lungs arise as ir.- 

 foldings of the posterior surface of the appendages of the 

 second abdominal somite, the lung cavity being essentially a 

 pit in the body-wall at the base of, and behind, the appemlages 

 m question. The development of the lamellx agrees strikingly 

 with Kingsley's observations on the origin of the gills of Liiiiiilus, 

 and lends considerable support to Prof. Lankester's well-known 

 theory. The trachea; develop behind the next pair of limbs at 

 the apex of a similar depression of the body-wall. In their 

 earlier stages these appendages show on their posterior surfaces 

 certain feeble undulations, which the author regards as aborted 

 M^- I .;c6, X'OI.. 5 I I 



lung- or giU-lamellx. The tracheal twigs arise as simple in- 

 growths comparable, in the author's opinion, with the infoldings 

 which produce the lamellx". Mr. Simmons concludes that the 

 lung-book condition is primitive, the tracheae of Arachnids 

 being derived from it. How far he is right in this conclusion, 

 and how far (if at all) Jaworowski has gone wrong, are 

 questions that we hope will not long remain undecided. 



A REDETERMINATION' of the temperature of greatest density 

 of water has recently been carried out by M. de Coppet, who 

 gives an account of his results in the AniiaUs de Chiniic el de 

 Physique. On account of the very slow change of density 

 about that temperature it is difBcult to determine it within a 

 hundredth of a degree Centigrade. The method adopted was a 

 modification of that of Despretz. A number of thermometers 

 were mounted in the lid of a cylindrical water vessel with their 

 bulbs at various distances from the bottom, and symmetrically 

 disposed about the axis. On immersing the vessel in a cold 

 water bath, a current was set up, passing down along the sides 

 and ascending in the centre. After a while the current stopped, 

 and then was reversed. The course of the current could be 

 followed by the readings of the thermometers. The water 

 having the greatest density would sink to the bottom, and the 

 temperature of the lowest bulb would be approximately that of 

 greatest density. But the temperature at which the lowest 

 thermometer stopped for a time was higher on cooling than on 

 heating. The curves exhibiting the two series of changes are, 

 however, symmetrical, and give the temperature of maximum 

 density as 3° '982 by the hydrogen thermometer under a pressure 

 of one atmosphere. 



A SIMPLE method of obtaining light of different wave-lengths 

 for use in polarimetric work is described by Landolt in the 

 Silziingiberichte of the Berlin Academy, No. 3S. White light 

 from an Auer's glow-lamp is passed through different absorp- 

 tion cells containing coloured solutions which can be readily 

 procured. Details are given of the preparation of five such 

 cells, by means of which red, yellow, green, light blue, and 

 dark blue light may be obtained. Examined spectroscopically, 

 the light is in each case found to consist of a band, and is not 

 by any means monochromatic ; if, however, the rotation be 

 less than 20°, or, with one or two of the cells, even if it be 

 considerably greater, the field of the polarimeler remains 

 apparently uniform in tint. The wave-lengths with which the 

 bands may be taken to correspond, were determined by using 

 the cells in a set of observations on the rotation of quartz, and 

 comparing the results with those obtained for the rotation of 

 quartz by Broch's method. The wave-lengths were thus ascer- 

 tained to be not far removed from those of the Fraunhofer lines 

 C, D, E, F, G. The instrument employed was a Laurent 

 half-shadow polarimeter fitted with a Lippich's polariser. -A 

 simple method of this kind has long been required for the 

 speedy investigation of rotatory dispersion. It is also of im- 

 portance to have a ready means of obtaining light of short wave- 

 length, which is of especial service when determining the rota- 

 tory power of feebly active substances. 



In a paper communicated to L'Elediicien (Paris), M. G. 

 Darriens gives an account of some recent experiments he has 

 made on the chemical reactions which take place in the 

 ordinary lead accumulator. To get an idea of the chemical 

 state of the negative plate of an accumulator, the author treated 

 a given weight of the negative plate of a fully-charged accumu- 

 lator with hydrochloric acid, and measured the volume of 

 hydrogen evolved. He then measured the volume of hydrogen 

 evolved when an equal weight of ordinary sheet-lead was dis- 

 solved in hydrochloric acid, and obtained practically the same 

 number as before. This experiment seemed to indicate tl.at 

 the negative plate of a charged accumulator consists of metal'ic 



