No. 1072, Vol. 42] 



NATURE 



71 



which the sympathetic system was plainly visible ; and from this 

 point the earlier and later steps in the process were traced. 



The first event to occur is the formation of the main sympa- 

 thetic cord, which arises in the mesoblast on either side of the 

 aorta, as a solid, unsegmented rod of fusiform cells produced by 

 the diflferentiation of cells in situ, and not at first connected 

 with the spinal nerves. In front, it ends abruptly at the level of 

 the first vertebral segment ; behind the suprarenal body (to 

 which it sends a considerable cellular bundle) it becomes indis- 

 tinct, terminating at the level of the hind limbs. 



Ttiis cellular column is, secondly, connected to the spinal 

 nerves by the formation of the white rami communicantes. 

 This is effected by the gradual growth of the inferior primary 

 divisions of the nerves, and their final division into somatic and 

 splanchnic branches. The splanchnic branch extends into the 

 splanchnic area, where it meets and joins the cellular sympa- 

 thetic cord. In the anterior part of the thorax it appears to 

 end wholly in the cord ; in the posterior thoracic and lumbar 

 regions it divides into two parts, of which one joins the cord, 

 the other passes beyond it. In both cases the fibres joining the 

 cord are directly connected with the component cells. Behind 

 the loins the splanchnic branches cease, and in the neck they do 

 not join the sympathetic cord. 



The formation of ganglia in the main sympathetic cord occurs 

 subsequently, and is due to (i) the function of the splanchnic 

 branches, the accession of a large number of nerve-fibres at the 

 point of entrance, and the consequent persistence of the com- ' 

 ponent cells (which are joined by these nerves) as ganglion cells ; ' 

 and (2) the anatomical relations of the cord to the bony seg- 

 ments, vessels, &c., over which it passes, and which indent it at 

 certain points. This view is supported by the evidence obtained 

 from dissections of human embryos in the 3rd, 4th, 5th, and 6th 

 months, where the cord forms a band, constricted irregularly at 

 considerable intervals, and from the adult structure, where the 

 "segmentation" of the sympathetic cord is apparent rather 

 than real. 



The cervical portion of the embryonic sympathetic cord 

 J separates at the origin of the vertebral artery into two unequal 

 parts. The smaller forms a fibro-cellular cord, and accompanies 

 that artery as the vertebral plexus ; the larger portion becomes 

 constricted off from the main sympathetic cord by the formation 

 of a fibro-cellular commissure, and forms the "superior cervical 

 ganglion." When the middle cervical ganglion is present, it 

 may be looked upon as a mass of the original cells of the sym- 

 pathetic cord which have been included in the growth of the 

 commissure. 



Posteiiorly the sympathetic cord gradually extends from the 

 level of the hind limbs, until in older embryos it can be traced 

 for a considerable distance along the middle sacral artery. It is 

 not joined by splanchnic branches behind the loins. 



The peripheral branches from the sympathetic cord arise as 

 cellular outgrowths which accompany the parts of the splanchnic 

 branches which do not join the sympathetic cord into the splanch- 

 nic area. They form considerable nerves, which follow the 

 main vessels, and produce parts of the splanchnic nerves, the 

 solar plexuses, &c., as well as the medullary portion of the 

 suprarenal body. The gray rami communicantes appear to 

 arise in the same way, and to belong to the same category. 



The main conclusions derived from the above investigations 

 are that in its development the sympathetic cord in mammals 

 is mesohlastic, formed in situ, and primarily unsegmented, and 

 unconnected with the spinal nervous system. 



Linnean Society, May i.— Mr. J. G. Baker, F.R.S., Vice- 

 President, in the chair. — Mr. Miller Christy exhibited and made 

 remarks on specimens of the so-called Bardfield oxlip, which he 

 had found growing abundantly not only in the neighbourhood 

 of Bardfield, Essex, but over a considerable area to the north 

 and west of it. — Mr. Buffham exhibited under the microscope 

 specimens of Myristrichia claviformis with plurolocular spor- 

 angia, and conjugation of Rhabdomena arctuatum, found upon 

 Zoitera marina. — The Rev. Prof. Henslow exhibited a col- 

 lection of edible MoUusca which he had recently brought from 

 Malta, and described the native methods of collecting and cook- 

 ing them. — Prof Stewart exhibited some spirit specimens of a 

 lizard, in which the pineal eye was clearly apparent. — Mr. 

 Sherring exhibited a series of excellent photographs which he 

 had taken near Falmouth, and which showed the effects of 

 limatic influence on the growth of several subtropical and rare 

 jilants cuhivated in the open air. — A paper was then read by 

 Prof. W. Fream, on a quantitative examination of water-meadow 



herbage. — This was followed by a paper from Mr. R. I. Pocojk, 

 on some Old World species of scorpions. 



Zoological Society, May 6.— Prof. W. II. Flower, F.R.S., 

 President, in the chair. — The Secretary read a report on the 

 additions that had been made to the Society's Menagerie during 

 the month of April 1890 ; and called special attention to two 

 examples of Simony's Lizard {Lacerta simonyi) from the rock of 

 Zalmo, Canaries, obtained by Canon Tristram, F. R. S., and pre- 

 sented to the Society by Lord Liiford. — Mr. Sclater exhibited 

 and made remarks upon the stuffed head of an Antelope, shot 

 by Commander R. A. J. Montgomerie, R.N., of H.M. S. 

 Boadicea, in June 1890, near Malimdi, on the East African coast, 

 north of Zanzibar. Mr. Sclater referred this head to what is 

 commonly called the Korrigum Antelope (Damalis senegalensis). 

 — Prof. Howes made remarks on a dissection of the cephalic 

 skeleton of Hatteria, and pointed out some features of special 

 interest exhibited by this specimen. These were the presence of 

 a pro-atlas and the existence of vomerine teeth, as in Palaofiat- 

 teria. — Two letters were read from Dr. Emin Pasha, dated 

 Bagamoyo, March 1890, and announced that he had forwarded 

 certain zoological specimens for the Society's acceptance. — Mr. 

 H. Seebohm exhibited and made remarks on a specimen of the 

 Eastern Turtle {Turtur orientalis), killed near Scarborough, in 

 Yorkshire. — Prof. F. Jeffrey Bell read the first of a series of 

 contributions to our knowledge of the Antipatharian Corals. 

 The present communication contained the descripti m of a parti- 

 cularly fine example of the Black Coral of the Mediterranean, 

 and an account of a very remarkable Antipathid from the neigh- 

 bourhood of the island of Mauritius. — A communication was read 

 from Mr. E. N. Buxton, containing notes on the Wild Sheep 

 and Mountain Antelope of the Algerian Atlas, taken during a 

 recent excursion into that country. These notes were illustrated 

 by the exhibition of fine mounted specimens of the heads of these 

 animals. — Mr. R. Lydekker read a note on a remarkable 

 specimen of an antler of a large Deer from Asia Minor, which he 

 was inclined to refer to an abnormal form of the Red Deer 

 {Cervus elapJius). — Mr. F. E. Beddard read a paper on the 

 minute structure of the eye in some shallow-water and deep-sea 

 species of the Isopod genus Arcturus. He pointed out that in 

 all the deep-sea forms there was some change in the visual ele- 

 ments which indicated degeneration. — Mr. E. T. Newton gave 

 an account of the bones of some small birds obtained by Prof. 

 Nation from beneath the nitrate beds of Peru. These bones seemed 

 to occur in considerable abundance, and nearly all appeared to 

 belong to one small species of Petrel, which it was thought most 

 nearly resembled Cymochorea leucorrhoa or C. markhami, the 

 latter of these being now found living on the coast of Chili. — A 

 communication was read from Dr. Mivart, F.R.S., containing 

 notes on some singular Canine dental abnormalities. — Mr. H. 

 Elwes read descriptions of some new Indian Moths. 



Chemical Society, May i.— Dr. W. J. Russell, F.R.S., 

 President, in the chair. — The following papers were read :— An 

 investigation of the conditions under which hydrogen peroxide is 

 formed from ether, by Prof. W. R. Dunstan and Mr. T. S. 

 Dymond. The authors have investigated the conditions under 

 which hydrogen peroxide is formed from ether (compare Richard- 

 son, Chem. Soc. Proc, 1889, 134), and found that ordinary ether, 

 prepared from methylated spirit, yields hydrogen peroxide when 

 exposed for several months to sunlight or the electric light. 

 Contrary, however, to the usual statements, pure ether (either 

 wet or dry) and ordinary ether which has been purified by treat- 

 ment with dilute chromic acid do not give a trace of hydrogen 

 peroxide when exposed to light under similar conditions. An 

 experiment shows that neither water nor dilute sulphuric acid 

 form hydrogen peroxide when exposed to light in contact with 

 air ; the authors refer the production of the peroxide from ether 

 to the presence of a minute quantity of some impurity in the 

 ether employed. Hydrogen peroxide is formed when ozone acts 

 on ether in the presence of water, and is also produced under 

 certain conditions during the slow combustion of ether in contact 

 with water. — Paradesylphenol, by Dr. F. R. Tapp, F.R.S., dnd 

 Mr. G. H. Wadsworth. — Note on Benedikt s acetyl values, by 

 Dr. J. Lewkowitsch, 



Mathematical Society, May 8.— J. J. Walker, F.R.S., 

 President, in the chair. — The President announced that a 

 member of the Society, Lieut. -Colonel J. R. Campbell, had 

 asked to be allowed to give a donation of ;^500 to the Society, 

 the sum to be invested, or otherwise made use of, for the good of 

 the Society, in any way the Council should judge best. On the 



