January 13, i8y8J 



NATURE 



263 



Milne-Edwards and Ilaime, but nevertheless was founded on 

 close similarity of structure. Other important characters in 

 common were now indicated, viz. the similarity of the earliest 

 growth-stages and of the method of budding. These were de- 

 scribed, and it was urged that there was now no reason to doubt 

 the relationship between Alveopora and Favosites other than that 

 which arose from the immense interval of time which had 

 elapsed since Favosites flourished and from the scarcity of inter- 

 mediate forms. One only had been described, viz. the genus 

 Koninckia from the Cretaceous. Mr. Bernard then discussed 

 the relationship of Alveopora with the recent PoritidiC, in which 

 f;imily it is usually classed. The author contended that Alveo- 

 pora and Poritidic stand about as far apart as possible in the 

 madreporarian system, and with regard to the evolutionary 

 stages of the madreporarian skeleton he concluded that the 

 original columniform polyp must be considered to have had the 

 lower portion of its body clothed with a stiff secretion which 

 formed a cup into which the upper flexible portion could be in- 

 vaginated This epithecal cup was the primitive madreporarian 

 skeleton. Within this cup — mainly by infoldings, at first simple, 

 but soon increasing in complexity— a new internal skeleton had 

 been developed which had largely superseded the primitive 

 epithecal skeleton. This internal skeleton, he thought, was as 

 much a product of the epitheca as the apodematous systems of 

 Arthropods are products of the chitinous cuticle. A discussion 

 followed, in which the Chairman and others took part. — Messrs, 

 H. and J. Groves communicated a paper on some CharacetE col- 

 lected by Mr. T. B. Blow in the West Indies, one of which 

 appeared to be new to science. Specimens of the plants de- 

 scribed were exhibited. 



Paris. 



Academy of Sciences, January 3. — M. A. Wolf in the 

 chair. — M. Van Tieghem was elected Vice-President for the 

 year 1898. — M. Chatin, the outgoing President, announced the 

 changes in the Members and Correspondents during the year 

 1897. — General method for determining fundamental stars and 

 latitude, by M. Loewy. A further developement of the method 

 announced at the previous meeting. — Histogenetic influence of 

 an anterior form, with respect to the regeneration of Descemet's 

 membrane, by M. L. Ranvier. It is known that the introduction 

 of a single crystal into a solution has a considerable effect in 

 causing crystallisation, and the present observations tend to 

 show that an analogous phenomenon may take place in organic 

 tissues. Observations were made upon the growth of the 

 membrane of Descemet and its endothelium in the cornea of a 

 rabbit, after partial destruction by incision and by a needle. 

 In the latter case, where the corneal layers attacked by the 

 needle have given an irregular surface, the endothelium, instead 

 of forming a simple cellular layer, appears in the form of small 

 masses, in which several layers of cells can be seen. The de- 

 finition of endothelium thus requires considerable modifica- 

 tion.— On the determination of the first terms of flexure of a 

 meridian instrument. Application to the meridian circle at the 

 Observatory of Paris, by MM. W. EbertandJ. Perchot. — On the 

 conformable representation of one surface upon another, by M. 

 G. Souslow. — On the velocity of propagation of a movement in 

 a medium at rest, by M. P. Vieille. A description of experi- 

 ments upon the velocity of the wave produced by exploding 

 varying charges of powder and fulminating mercury in a steel 

 tube. The figures obtained show that as the initial condensa- 

 tions increase, the mean velocities of propagation on a length of 

 four metres aho increase from values about the velocity of sound 

 up to four times that speed. — On a new method of in- 

 terferential spectroscopy, by MM. A. Perot and Ch. Fabry. 

 The interferential spectroscope is composed of two plates of 

 plane glass with silvered faces opposed, the distance and orienta- 

 tion of which can be exactly regulated. The rings produced are 

 observed at an infinite distance, the system being lighted by a 

 slightly converging bundle of rays. With this apparatus M. 

 Michelson's statement that the green ray of thallium is double 

 has been verified. — On the mechanism of the discharge of con- 

 ductors struck by the X-rays, by M. G. Sagnac. The surface of 

 a metal, M, struck by the X-rays emits new rays termed secondary 

 rays of the metal M. Each element of volume of gas adjacent 

 to the metallic conductor is rendered capable of conducting 

 electricity, both by the incident X-rays and by the secondary 

 rays. — On a simple method for directly transforming typo- 

 graphical plates and other objects in feeble relief into photo- 

 graphs, by M. Adrien Guebhard. — On the isocyanic ethers and 

 the heat of formation of liquid isocyanic acid, by M. Paul 



NO. 1 472 VOL. 57] 



Lemoult. The heats of formation were determined of the iso- 

 cyanates of methyl and ethyl by the method of the calorimetric 

 bomb. — On a new cyclic ketone methylcylohexonone, by M. A. 

 Behal. This ketone is one of those obtained from wood oil. 

 Oxidation with potassium permanganate gave only acetic and 

 levulic acids. The benzoyl derivative and oxime were prepared. 

 — Preliminary note on the origin of the subrenal capsules of 

 lophobranchial fishes, by M. Iluot. The subrenal capsules have 

 been u.sually regarded as arising from the epithelium of the 

 coelom, but the study of the development of these organs in the 

 embryos of Syngnattis Diiinerilii, leads to the conclusion that 

 they arise from two sunk diverticula each of which is a bud from 

 the posterior portion of a Wolf's canal. — On the origin of the 

 setigerous bulbs and the nephridia in Annelids, by M. Aug. 

 Michel. In the caudal regeneration of the Annelids, the seti- 

 gerous bulbs are ectodermic and the setigerous sacs are meso- 

 dermic ; the nephridia are of a neutral origin, ectomesodermic. 



Amsterdam. 

 Royal Academy of Sciences, November 27, 1897. — Prof, 

 van de Sande Bakhuyzen in the chair. — Prof, van der Waals 

 gave an approximate rule for the course of the plaitpoint-curve 

 of a mixture. The curve constructed according to the rule given 

 will correspond very closely with the actual plaitpoint-curve in 

 the case of all those mixtures, which present the circumstance 

 that a maximum or a minimum, tension occurs, if the components 

 have a certain ratio to each other, as is the case with mixtures 

 of N.>0 and C.^H,;. The curve for the said mixtures, according 

 to Kuenen's observations, is explained in all its details by this 

 rule. — Prof. Moll on an inquiry by Mr. Van Wisselingh into the 

 nucleolus of Spirogyra. The principal results of this inquiry 

 are : ( i) besides the usual form of karyokenesis Spirogyra crassa, 

 Kiitz, has also a second form, in which no nuclear segments are 

 produced ; (2) in the division with segmentation ten out of the 

 twelve segments originate in the nucleus itself, while two 

 originate in the nucleolus ; (3) in the case of nuclear division 

 with segmentation the nucleolar segments have each a resistant 

 thread, by which they are distinguished from the rest. The 

 resistant threads divide longitudinally, like the segments them- 

 selves, and the two halves contribute in the daughter nucleus 

 towards the formation of the new nucleolus. In the case of 

 nuclear division without segmentation the nucleolus also produces 

 two resistant threads, which in the division behave in exactly 

 the same way as in karyokenesis with segmentation. — Mr. 

 Eykman on the influence of the seasons on coinbustion of 

 nutritive matter in man. The speaker communicated the results 

 of a comparative inquiry into the respiratory exchange of gases 

 in winter and in summer. With the nine persons, upon whom 

 he experimented, the speaker found the average consumption of 

 oxygen, when they were in a state of bodily rest, to be no 

 smaller in summer than in winter, and concludes, also, on the 

 ground of previous investigations made by him in India, that in 

 man there exists no appreciable chemical regulation of heat. — 

 Prof. V. A. Julius presented on behalf of Mr. N. G. van Huffel 

 a short paper on magnetic hysteresis in a long soft iron bar. 

 Round the middle of the bar was a primary coil ; a secondary 

 coil could be placed at various distances from the priiTiary one. 

 At a certain moment, varying from 1/3 to 2 seconds after the 

 primary circuit was closed, the secondary one was for xJtt second 

 brought in contact with a ballistic galvanometer. It appeared 

 that the rate of change of induction reached a maximum at a 

 certain distance from the middle of the bar, and that the maxi- 

 mum displaced itself with the increase of the time from the 

 middle towards the ends of the bar. — Prof, van Bemmelen com- 

 municated on behalf of Mr. Schreinemakers the results of aiv 

 inquiry into the equilibrium in systems of three components, in 

 which two and three liquid phases occur. — Prof Kamerlingh 

 Onnes presented on behalf of Dr. W. van Bemmelen a paper, 

 entitled "a provisional notice of new acquisitions of older observa- 

 tions of magnetic variation, among others by Parmentier in 1529, 

 Cavendish in 1587, and by French navigators in the Pacific 

 about the year 1700." — Prof van der Waals presented {a) on 

 behalf of Prof. Dibbits a paper by Dr. A. Smits, on an iastru- 

 ment for keeping the tension above a boiling liquid constant. 

 The space in which the space is to be kept constant, is connected 

 with a U-shaped barometer. When the pressure decreases, the 

 mercury rises in the shorter limb and, in consequence of this, a 

 galvanic circuit is closed, through which a blowing-apparatus is 

 put in action ; when the pressure increases, a sucking-apparatus 

 is put in action by another galvanic circuit. When the oscilla- 



