January 12, 191 1] 



NATURE 



301 



:niform character and thickness, but at Mansfield it is 

 pparently absent. At the same place the limestone be- 

 omes sandy, forming the Mansfield Sandstone. These 

 ,vo phenomena can be best explained by supposing that 

 : river deposited a sandbar at Mansfield during Permian 

 ;mes. North of Mansfield the Middle Marl becomes 

 ormal again. Near Cuckney, the Upper Magnesian 

 Limestone first appears as a very thin bed, and the lime- 

 stone arises as thin lenticular bands in the passage-bed. 

 It is believed that the Upper Magnesian Limestone and 

 Upper Marl of the northern part of the outcrop are the 

 time equivalents of the Bunter of South Nottinghamshire. 



t^oyai Microscopical Society, December 21, 1910. — Mr. 

 E. J. Spitta, vice-president, in the chair. — ^W. R. 

 Traviss : A small microscope lamp, particularly suited 

 for opaque objects and dark-ground illumination with high 

 powers. The light used was a small inverted incandescent 

 burner carried at the extremity of a short arm, that could 

 be easily moved up and down on a standard. The light 

 could be brought very close to the table or raised to 

 illuminate opaque objects on the stage. — M. J. Allan : 

 An easy method of treating printing-out paper (P.O. P.) 

 for all kinds of photography. The author recommends 

 that the prints be washed in a strong solution of salt, 

 then placed in a saturated solution of hypo, after which 

 they are to be washed in running water. — C. H. Higg^ins : 

 \ new system of filing slides.- — .\. j\. C. E. Merlin : The 

 measurement of Grayson's new ten-band plate. The plate, 

 comprising ten bands running from i/ioooth to 1/ 10,000th 

 of an inch, had been ruled by an improved machine, and 

 was found to be much better even than Grayson's earlier 

 productions. The author in measuring the bands used a 

 selected objective of 1-32 N-A.. having an initial magnifi- 

 cation of 143 on a lo-inch tube. S. Nelson-Powell screw 

 setting micrometer, which is alone suitable for the pur- 

 pose, was used. The result obtained was that the varia- 

 tion from the mean in the spacing of the lines did not 

 exceed i '230,000 inch. The mean diameter of the lines 

 was 000002488 inch. The author also made a series of 

 measurements with i-inch, J-inch, and ^-inch objectives, 

 and came to the important conclusion that low powers 

 were unsuited for micrometry. — ^Jas. Murray : Some 

 African rotifers — Bdelloida of tropical .Africa. Thirty- 

 three species of bdelloids were obtained from dried moss 

 sent by Mr. .A. .Allan and Sir Philip Brocklehurst from 

 British East -Africa. Nine of the species are new to 

 science. Several of them have very distinct characters 

 not previously noted for any bdelloids. Harbrotrocha 

 caudata has a tail-like process, the function of which is 

 unknown. The animal secretes a protective shell, and the 

 " tail " is enclosed in a slender tube open at the end, so 

 that the shell has two openings. ^. acornis has no trace 

 of spurs, otherwise universal in the order. Several other 

 species approach it in this respect, having the spurs re- 

 duced to minute papillae. H. auriculata, when feeding, 

 has at each side of the head a peculiar ring-like auricle, 

 giving it the appearance of a two-handled vase. The 

 nature and function of the auricles remain unknown. 

 Their form, even, is difficult to interpret, as they present 

 aoparently contradictory appearances from different points 

 of view. The bdelloids take a very important place in 

 moss-faunas. In every country they are abundant, and in 

 most regions there is a fair proportion of peculiar species. 

 When more fully known the bdelloids seem likelv to prove 

 a group of hitherto unsuspected importance, both in point 

 of numbers and diversity of forms. .Ml these moss.' 

 dwellers can revive after desiccation. The adult animals 

 become dormant when deprived of moisture, and revive 

 when remoistened. It is not, as Zacharias concluded from 

 his experiments in 1886, that the survival of the species 

 is effected by means of eggs. 



Manchester. 

 Literary and Philosophical Society, December 13, iqio. 

 — Mr. Francis Jones, president, in the chair. — Miss 

 Margaret C. March : Preliminary note on Unio pictorum, 

 v. tumidus, and D. cygnea. The form of the British 

 unionids can be shown to be dependent on current and 

 soil, and is therefore useless for systematic purposes when 

 taken alone. The umbonal markings of these animals 



NO. 2150, VOL. 85] 



merge into one another, and are therefore useless 

 specifically. Phylogenetically, they show that U. pictorum 

 is most archaic, anodon least, tumidus being intermediate. 

 The edentulousness of American anodons illustrates 

 heterogeneric homaeomophy. The ornament and dentition 

 of unionids show relationship to trigonids, and a descent 

 from a pre-trigonid ancestor. — D. M. S. Watson : Notes 

 on some British Mesozoic crocodiles. The author dis- 

 cussed some systematic and nomenclatural difficulties, 

 recording the occurrence of a new variety of Metrio- 

 rhynchus hastifer in the Corallian of Headington, of 

 M. hastifer itself in the Kimmeridge Clay of Britain, 

 and discussed Petrosuchus laevidens and Steneosaurus 

 stephani. — Prof. F. E. Weiss : Sigillaria and Stigmari- 

 opsis. The author cKhibited some specimens of axes of 

 Sigillaria associated with stigmarian bark. From the re- 

 peated occurrence of these specimens it was suggested that 

 they represented the base of the aerial or the subterranean 

 axes of Sigillaria, probably of the Eusigillaria type. The 

 secondary wood was more copiously developed than is 

 general in the aerial axes. The primary wood was of 

 sigillarian type, so that these stigmarian axes have centri- 

 petal primary wood, and their pithcasts would be striated 

 like those described for Stigmariopsis. It was noticed that 

 in some instances small axes were found in contiguity, 

 and apparently in continuity, with the main axes. These 

 smaller axes resemble the ordinary stigmarian axes very 

 nearly, and do not show the centripetal primary wood of 

 the main axis, but only a few fine tracheids in the pith 

 region. 



P.ARIS. 



Academy of Sciences, January 3. — M. Armand Gauiier 

 in the chair. — The Fanny Emden prize (3000 francs). 

 This prize will be awarded for the current year for the 

 best work dealing with hypnotism, suggestion, and 

 generally physiological actions capable of being exerted 

 at a distance from the animal organism. In the special 

 circumstances, memoirs on this subject will be received 

 up to June I. — M. Bertin : The general laws of 

 accelerated or retarded motion of a ship following on a 

 change in the power of the engine. The formulae 

 developed from theoretical considerations are compared 

 with experimental results obtained by the vessel Patrie ; 

 the agreement is satisfactory. — Pierre Termier : Remarks 

 on the geological map of the Alps. — M. de Forcrand : 

 The thermochemical study of some binary compounds of 

 the metals of the alkalies and alkaline earths. A table 

 is given, summarising recent determinations by various 

 authors, giving the heats of solution and formation of the 

 chloride, brcwnides, iodides, and fluorides of lithium, 

 calcium, strontium, barium, sodium, potassium, rubidium, 

 and caesium, and some general conclusions are drawn 

 based on these data. — Ernest Esclang^on : A rotating 

 governor for fixed or variable velocity. The method of 

 regulation, described and illustrated, has been designed for 

 the control of meridian and equatorial telescopes. It 

 permits of easy regulation when in actual motion. — G. 

 Tzitx^ica : The W congruences. — Michel de Domeczky : 

 The theory of symmetrical functions.— C. Popovici : 

 Stable permanent movements. — Leinekugel le Cocq : The 

 general theory of two indeformable suspended solids, from 

 which are derived formulae applicable to all systems of 

 rigid suspension bridges. — O. Boudouard : The testing of 

 metals by the study of the damping of vibratory move- 

 ments. Details of experiments on specimens of iron and 

 steel containing up to i-o per cent, of carbon, and the 

 thermal treatment of which is exactly determined. — C. E. 

 Quillaume : The definition of the practical electrical 

 units. — A. Lebedefr : The extraction of zymase by simple 

 maceration. A simple method is described of obtaining 

 zymase not requiring the use of costly materials. — L. 

 Bruntz and L. Spillmann : The physiological significance 

 of the vital coloration of leucocytes. The so-called vital 

 coloration of leucocytes appears to represent, as in phago- 

 cytosis, a defensive physiological action, and this general 

 phenomenon is carried out both in vertebrates and inverte- 

 brates by identical processes. — Henry P^nau : The cyto- 

 logy of Bacillus megatherium. — D. Roudsky : The possi- 

 bility of rendering Trypanosoma lewisi virulent for other 

 rodents besides the rat. 



