August 4, 1S98] 



NATURE 



335 



SCIENTIFIC SERIALS. 



American Journal of Science, July. — The origin and signi- 

 ficance of spines ; a study in evolution, by C. E. Beecher. The 

 importance of spines lies not in what they are, but in what they 

 represent. They are simply prickles, thorns, spines or horns. 

 They represent a stage of evolution, a degree of differentiation 

 in the organism, a ratio of its adaptability to its environment, a 

 result of selective forces, and a measure of vital power. Tracing 

 the various groups of forms through their geological develop- 

 ment, it is noticed that each group began its history in small, 

 smooth, or unornamented species. As these developed, the 

 spinose forms became more abundant until after the culmination 

 of the group is reached, when this type either became extinct or 

 was continued in smaller or less specialised forms. — Electrical 

 discharge from the point of view of the kinetic theory of matter, 

 by J. E. Moore. When gaseous matter moves in a stream in 

 any definite direction, the pressure of the gas in that direction 

 is increased by an amount proportional to the square of the 

 velocity of translation The author proves experimentally that 

 the pressure in the direction of discharge is greater than in 

 either of the directions at right angles, by an amount depend- 

 ing upon the velocity of the discharge stream. — Further separ- 

 ations of aluminium by hydrochloric acid, by F. S. Havens. 

 Describes the separation of aluminium from zinc by the action 

 of hydrochloric acid gas in aqueous ethereal solution. Also the 

 separation of the same metal from copper, mercury and bismuth! 

 — On the origin of the corundum associated with the perido- 

 tites in North Carolina, by J. H. Pratt. The corundum was 

 held in solution by the molten mass of the dunite when it was 

 introduced into the rock, and separated out among the first 

 minerals when the mass began to cool. — The winter condition 

 of the reserve food substances in the stems of certain deciduous 

 trees, by E. M. Wilcox. Material of the Ltrioc/endr on collected 

 in October was found to have an abundance of starch in the 

 cells of the cortex, but none in the cells of the medullary sheath, 

 and but few grains in the cells of the wood parenchyma and 

 medullary rays. The cells immediately below the growing 

 point of the stem contained no starch at this time. November 

 and December showed a gradual increase in the amount of the 

 starch in the medullary sheath, but a marked decrease in the 

 amount present in the cortex. At the end of February starch 

 began to appear again in the cortex, but more especially in the 

 cells beneath the growing point. 



Annalen der Physik und Chemie, No. 6. — The spectra of 

 iodine, by H. Konen. The author investigates all the different 

 spectra of iodine obtainable by the use of arcs, vacuum tubes, 

 heated vessels, sparks, and fluorescence. He uses the photo- 

 graphic method and an excellent concave grating, and succeeds 

 in cataloguing some 360 lines, extending from 3030 to 5800. — 

 The Leidenfrost drop, by J. Stark. By inserting a drop in the 

 spheroidal state, the hot metallic plate, and a telephone in an 

 electric circuit, the author shows that the drop performs oscilla- 

 tions with respect to the layer of vapour which prevents its 

 evaporation. In the final stages the plate is intermittently 

 wetted. The oscillations are due to differences of surface 

 tension between the hot and cold portions of the drop. — The 

 electromotive behaviour of chromium, by W. Hittorf. Chromium 

 has a different electric behaviour, accordingly as it is in the state 

 to form the monoxide, the sesquioxide, or the peroxide. At 

 ordinary temperatures, and in solutions from which it does not 

 disengage hydrogen, it behaves like a noble metal. But at high 

 temperatures it reduces all the other metals except zinc from 

 their fused salts, and forms its own lowest combination. Fresh 

 surfaces of the metal are in the active state. — The Weston 

 standard cell, by P. Kohnstamm and E. Cohen. The E.M.F. 

 of the cadmium cell shows certain irregularities below 15 degrees, 

 which are due to the fact that the constitution of the cadmium 

 sulphate undergoes some change at that temperature. This 

 change does not affect the water of crystallisation, but cor- 

 responds to the change undergone by sulphur at 95 degrees. At 

 temperatures between 15 and 70 degrees the Weston cell is 

 superior to the Clark standard. — On thermophones, by F. 

 Braun. The momentary expansions and contractions pro- 

 duced in a strip of brass or a bolometer by a variable current 

 may be used for the transmission of sound. For this purpose 

 the bolometer is put in circuit with three or four accumulators 

 and a microphone. The effect may be greatly increased by 

 increasing the steady current. — Electric discharge in rarefied 

 gases, by W. Wien. From experiments on the electrostatic 

 deflection of kathode rays, the author calculates their velocity 



as one-third that of light. Goldstein's canal rays are the pro- 

 longation backwards of the kathode rays, and like them are 

 subject to magnetic and electrostatic deflection. — Polarisation of 

 Rontgen rays, by L. Graetz. Polarised X-rays cannot be pro- 

 duced even by using a fluorescent body as an anti kathode, 

 although such bodies are known to emit polarised light. 



SOCIETIES AND ACADEMIES. 



London. 



Royal Society, June 16.—" The Stomodseum, Mesenterial 

 Filaments, and Endoderm of Xenia." By J. H. Ashworth, 

 B.Sc, Demonstrator in Zoology, Owens College, Manchester. 

 Communicated by Prof Hickson, F. R.S. 



The Xeniidre are distinguished from all other Alcyonaria by 

 their soft fleshy consistency and non-retractile polyps. 



The stomodseum of each polyp is moderately long (18 -2 '2 

 mm.), and has a well-marked ventral groove or siphonoglyphe, 

 the cells of the lower third of which bear long flagella. Among 

 the cells forming the remainder of the wall of the stomodreum 

 are numerous " goblet cells," which have not hitherto been 

 noticed in the stomodaeum of the Alcyonaria. These cells 

 generally appear empty, having discharged their secretion,, 

 which, in some cases, can be seen issuing from the cell into the 

 cavity of the stomodceum. These secreting cells occur chiefly- 

 in the middle and lower portions of the stomodyeum, and are- 

 most abundant on the lateral walls near the siphonoglyphe. 



These "goblet cells" of the stomodreum are the only 

 secreting cells connected with the digestive cavity, as the six 

 thick ventral and lateral mesenterial filaments, which bear the 

 gland cells in other Alcyonaria, are absent in all polyps of this.. 

 Xenia. The two dorsal mesenterial filaments are present and 

 have a similar course and structure to those of A/cyonium. 

 Wilson and Hickson have shown that the ventral mesenterialij 

 filaments bear the cells which produce the digestive secretion.. 

 The absence of these filaments in this Xenia is probably cor- 

 related with the presence of gland cells in the stomodaeum,. 

 which from their position and structure appear to perform some 

 digestive function. 



The siphonozooids which occur in Pennatulids and some other 

 Alcyonaria are the only recorded examples of polyps in which 

 the ventral and lateral mesenterial filaments are absent. Ac- 

 cording to Wilson, these siphonozooids derive their food supply 

 from the autozooids or feeding polyps, and therefore do not 

 require cells to produce a digestive secretion. 



The endoderm cells which line the coelentera and the cavities, 

 of the tentacles contain numerous small vacuoles which give the 

 protoplasm a reticulate appearance. Among the ordinary 

 endoderm cells are numerous cells, the inner or free end of 

 which is produced into a long pseudopodium, which is from four 

 to eight times as long as the basal portion of the cell. The 

 pseudopodia, which appear to be flexible, may attain a length, 

 of •12 mm. They are not vacuolated, their protoplasm being 

 homogeneous or very finely granular. The basal part of the- 

 cell from which the pseudopodium arises has the reticulate 

 protoplasm of an ordinary endoderm cell, and the nucleus of 

 the cell is situated in this portion. These pseudopodia-bearing 

 cells are very numerous and occur in all parts of the endoderm, 

 lining the coelentera and the cavities of the tentacles. 



Edinburgh. 

 Royal Society, July 18. — Lord McLaren in the chair. In 

 a note on the electrolysis of ethyl potassium diethoxysuccinate, 

 Prof. Crum Brown and Dr. H. W. Bolam" showed that the 

 electrolytic synthesis of dibasic acids applies to the unsym- 

 metrical diethoxysuccinic acid 



COOH— C(OEt)2-CH.,— COOH, 

 although it does not apply to monoethoxysuccinic acid 



COOH— CH(0Et)-CH2— COOH. 

 — Mr. W. W. Taylor communicated a note on the freezing 

 point of aqueous solutions of sodium mellitate. The work was 

 undertaken at Prof. Crum Brown's suggestion to test Van 

 t' Hoff's theory of the depression of the freezing point of solutions 

 of electrolytes. The molecular depressions obtained experi- 

 mentally for solutions of different concentration were from 410 6 

 times the normal molecular depression, I '87. According to 

 the theory the greatest possible depression is 7 times the 

 normal. — Sir John Murray, K.C.B., presented two papers — one 

 on the deposits collected by the s.s. Britannia in the Western 



NO. I 50 1, VOL. 58] 



