4^6 



NA TURE 



[August 30, 1894 



MaicloHi probably originate within cells, from which they are 



Prof. G. Gilson(Louvain\ on the nephridial ducts o{ Owenia. 



The Rev. T. K. K. Stebbing, on zoological publication, &c., 

 suBgested that the leading biological societies should arrange 

 the work of publishing between them, so as to avoid the over- 

 lapping which now lakes place. He proposed that for every 

 country there should be a single authorised journal to receive 

 the names of new genera and species with brief descriptions, 

 all claimi to priority being dependent on the date of this record. 



Mr J. T. Cunnineham, on the significance of diagnostic 

 characters in the Pleuronectida;, discussed the evolution 

 of the characters which distinguish flat-fishes into sub- 

 families, genera, and species. He considers that the spe- 

 cific and many of the generic characters are not known 

 to be adaptaiional, and are more probably due to gene- 

 rative isolation and divergent variation. His general 

 conclusion is that animal variation is to be regarded as the 

 resultant of two opposing inflaences, one internal and one ex- 

 ternal to the organism. The one is the internal tendency to 

 definite divergent variations which have no direct relation to the 

 struggle for existence, the other is the direct influence of adap- 

 tation, whether due to the selection of individuals or to the 

 direct modification of individuals. 



Mr. Goodrich described some of the methods adopted recently 

 in displaying specimens in the zoological part of the Oxford 

 University Museum. Dr. F. A. Dixey, on the plantar surface 

 in infants, showed that his investigations on the skin of the 

 foot in very young infants who had never walked, do not lend 

 any support to the view that acquired characters can be trans- 

 mitted by heredity. 



Mr. \V. E. Collinge, in a paper on the relations of the 

 cranial nerves to the sensory canal system, showed that 

 the canals are innervated in the Elasmobranchs chiefly by 

 the facial nerve, in the Ganoids by the trigeminal and 

 facial, and in the Teleostei chiefly by the trigeminal. Dr. 

 H. B. Pollard exhibited, with remarks, models of the 

 cranial skeletons of some rare South American and African 

 siluroid fishes, made after the method of Born, with the ad- 

 dition that they were electroplated in order to give them 

 snflicient firmness. Attention was drawn chiefly to the barbules 

 round the mouth. These were maintained to be the homologues 

 of the oral tentacles of Myxiiu and the cirri of Amphio.xus, and 

 a new theory of the origin of the head in Verlebrata, termed 

 the cirrhostomial theory, was based on these homologies. The 

 author contrasted this theory with the old vertebral theory of 

 Goethe and Oken, and the subsequent theories of Gegenbaur, 

 Balfour, v. Wijhe, and others. 



GEOGRAPHY AT THE BRITISH 



ASSOCIATION 

 AT the Oxford meeting the popularity of the Geographical 

 ■^ Section showed no abatement. Crowded meetings were the 

 rule, even when papers of a severelyscientific characterwere being 

 read. This may be explained to some extent by the favourable 

 situation of the seclion-room in close proximity to the reception- 

 room ; but perhaps the general use of lantern illustrations had 

 more to do with it. liy means of effective lantern diagrams the 

 audience was able to follow with interest and pleasure, papers 

 on detailed oceanography and climatology. The characteristic 

 of the meeting may !« given as the general high level of the 

 papers offered, and the interesting discussions to which they 

 frequently g.ive rise. 



The rrc>idcnt, in his address, dealt with oceanography in its 

 widest sense. ~" ' •■ ■ >■ Mowed bya number of papers of similar 

 character, til ^cr scope. Unfortunately, it was found 



impossible f'T , , i ■•imilar subjects to be taken in all cases 



on the same day, as the convenience of the authors frequently 

 made it necc'sary to alter the provisional arrangements which 

 had been made. Mr. II. N. Dickson gave an account of the 

 iharc he had taken on board H.M.S. ync/vi/in the international 

 oceanographical observations initialed by Prof. Petterson, of 

 Stockholm. The general conclusions arrived at were as 

 follows : — 



While the Atlantic current fliwingover the Wyville-Thom- 

 ■on ridge attains its maximum velocity in winter, its speed is 

 maintained during summer by the greater w.irmtli of the upper 

 layers of water in the Atlantic, and consequent higher level of 



NO. 1296, VOL. 50] 



the surface of that ocean compared with the Norwegian Sea. 

 Passing over the ridge, the .\llantic current is cooled by mixture 

 with the cold water of the Norwegian sea lying at the bottom of 

 the Faeriie-Shetland Channel, and loses its horizontal motion. 

 The warmer the Atlantic current the more rapidly does this 

 mixture take place. Hence in a hot, windless summer a mass 

 of Atlantic water, extending to a great depth, tends to collect 

 on the northern and north-western edge of the North Sea bank. 

 At all seasons Atlantic water is drawn from the Faeroe-Shet- 

 land Channel and forced into the North Sea by the tides 

 between Orkney and Shetland. The tidal streams run north-west 

 and south-west, and an eddy is formed to the north-west of the 

 Orkneys, into which North Sea water is drawn, and perhaps 

 also water from below. As the season advances the surface 

 water of the North Sea becomes warmer, the upper layers pro- 

 bably receive smaller supplies of fresh water, but they become 

 specifically lighter than the under layers, which they protect from 

 the warming influences of the atmosphere. The upper layers 

 becoming ultimately warmer than the Atlantic current, the sur- 

 face of the North Sea becomes higher, and the surface water 

 spreads outwards into the Faetbe-Shetland Channel, checking 

 the surface supply of Atlantic water. Meanwhile, the mass of 

 Atlantic water, collecting at the edge of the North Sea Bank, 

 seeks entrance into the North Sea. Mixing with the cold 

 bottom water already there, it increases its salinity, but reduces 

 its specific gravity by warming it, and, at a certain stage of 

 mixture, the temperatures and salinities of the two waters com- 

 bine to form a ridge or axis of maximum specific gravity. This 

 axis, which probably runs north-east from Shetl.ind in the end of 

 May or in June, turns slowly toward a north to south direction, 

 and moves eastward. As it retreats, Atlantic water is gradually 

 admitted round the north end of the .Shetlands, p.asses down the 

 east side of the groups, joins the tidal stream at the south end, 

 and, guided by the axis of heavy water, is distributed along 

 the east coast of Scotland, probably during July and .\ugust. 

 Liter in the summer, as the axis retreats still further, the Atlantic 

 water is probably distributed more towards the eastwarH, per- 

 haps until the latter part of September, when the diminishing 

 supply from the F.ieroe Channel, and the increasing outflow 

 from the eastern side of the North Sea, bring about a gradual 

 return to the conditions with which we started. Obviously the 

 controlling conditions are complex, but it appears that the 

 greater the winter cold and the spring supply of ice-cold water 

 from the continent, the more slowly will .\tlantic water penetrate 

 into the North Sea below the surface ; and the warmer the 

 summer, the more will the surface supply be checked. At the 

 same lime, the warmer the summer the larger the quantity of 

 Atlantic water seeking admission, and the greater its thermal 

 power to drive back the axis of maximum weight. 



M. A. Delebccque, of Thonon, sent an account of his 

 methods of surveying and constructing balhymetrical maps of 

 the French lakes, a series of which was exhibited. The geo- 

 graphical conditions of the English lakes were described bv Dr. 

 H. R. Mill, and in the discussion which ensued, Prof. Guido 

 Cora, of Turin, look a leading part. Mr. J. V. Buchanan, 

 F. R.S. , sent an account of the researches being carried out by 

 the Prince of Monaco and himself on hoard the Prince's yacht 

 Princesse Alice, in the Mediterranean and North All.antic, which 

 received considerable attention. Me found that even at a dis- 

 tance of 600 miles south-west of the Strait of (librallar the salt 

 water from the Mediterranean occupied the lower half of the 

 whole depth, the upper half alone being occupie 1 by Atlantic 

 water. Numerous observations were made in the narrowest 

 part of the Straits, with the eflcct of defining the manner in 

 which the surface current of Atlantic water entering the 

 Mediterranean is related to the deeper current of dense water 

 escaping to the ocean. 



Dr. lohn Murray gave a discourse on the geographical and 

 balhymetrical distribution of organisms in the ocean, focussing 

 all our knowledge of the distribution of marine life, and con- 

 cluding with the belief that the existing distribution is a result 

 of the gradual restriction of a universal fauna which flourished 

 in a climate of worldwide warmth, possibly due to the 

 larger size of the sun. This paper gave rise to an animated 

 discussion. .Mthough not formally organised, this was practi- 

 cally a joint discussion between .Sections D and K, the par- 

 ticipants in the discussion comprising Dr. Gunther, Mr. P. L. 

 Sclater, Dr. O. Maas, Canon Norman, Dr. II. O. Forbes, 

 and Mr. Garslang. 



Papers dealing wilh new exploration were unusually numerous. 



