October 22, 1896J 



NA TURE 



60: 



ZOOLOGY AT THE BRITISH ASSOCIATION. 



CKCTION D met on the afternoon of Thursday, Septeml)er 

 17, in the Zoology theatre, University College, the Presi- 

 dent's address having been given in the Arts theatre in the 

 morning. The principal feature of ihe Section was the large 

 number of discussions, these occupying the mornings throughout 

 the meeting, and two of them being in conjunction with the 

 -eclions of Physiology and liolany (I and K). 



Thursday, Scplembtr 17. — The first paper was by Mr. R T. 

 (iiinther, on Roman oyster culture. The author's facts were 

 drawn both from classical writings and, also, from pictorial repre- 

 sentations on ancient vases. Some of the latter gave fairly in- 

 telligible pictures of the processes used, and .showed what means 

 were adopted for attaching and preserving the young oysters. 

 I le believed that there was good evidence to show that ropes and 

 oiher similar substances were used for the former purpose. 



Mr. Walter (iarstang read a preliminary communication on 

 ihe utility of specific characters in the Brachyurous Decapods, 

 referring, however, particularly to ihe crabs. The object of the 

 in()uiry was to ascertain the essential meaning of the denticula- 

 tion of the edges of the frontal area of the carapace. The 

 author first drew attention to ihe fact that in some crabs the 

 respiratory current was from before backwards — the reverse of 

 that believed to have applied in all cases by Milne Edwards. 

 This led to the inference that the function of the .serration was 

 lo filter off solid matter from the water entering the branchial 

 chamber from before. This conclusion was supported l>y the 

 fact that the denticulations were characteristic essentially of the 

 burrowing crabs, in which, as being buried in .sand, it was im- 

 portant that some filtration of the respiratory current should be 

 provided for, in order to prevent ihc otherwise inevitable block- 

 ing up of the respiratory chamber by foreign matter. When, 

 owing to (he habits of a crab, the serrations should a priori be 

 absent, they were, in fact, not found. The conclusion was 

 that the denticulations on the frontal area of the carapace were 

 functionally correlated with the flow of the respiratory current 

 from before backwards, thus confirming the theory of natural 

 selection by proving the utility of specific characters which 

 would otherwise have been concluded as useless. In the discus- 

 sion which followed. Prof. W. F. R. Weldon remarked how 

 necessary it was to exercise caution before concluding that any 

 specific characters were useless. Dr. C. IL Hurst drew atten- 

 tion to the anterior position of the renal aperture in Crustacea, 

 which he thought implied a forward, and not a backward, flow 

 of the respiratory current. lie suggested that this might also 

 be a diagnostic character in determining the direction of the 

 flow, as it would doubtless be essential that the products of the 

 nephridia should be carried away from the gills. The Rev. 

 T. R. R. Stebbing stated that in many Crusiacea the position of 

 the renal aperture could not possibly be correlated with the 

 flow of the respiratory current, and that, therefore, its forward 

 lh)sition had no significance in this connection. 



The following reports of Committees were then presented : 

 (i) "The Zoology of the Sandwich Islands," by Prof. A. 

 Newton. Three papers had been published as the result of the 

 work of the Committee's collector, on the Orthoptera, Slugs, 

 anil Earthworms. Prof. Newton empha.sised the importance of 

 proceeding with the work as rapidly as possible, as the fauna 

 in some parts was being partially destroyed by animals intro- 

 duced into the islands. (2) " The Occupation of a Table at the 

 Marine Biological Laboratory. Plymouth." The report dealt 

 with the work of Mr. Ceorge Brebner on the Algae of the Ply- 

 mouth district. (3) " Zoology and Botany of the West India 

 Island.?." Five papers had been published as the result of the 

 work of the Committee, and other papers were in hand on the 

 Isopod Crustacea and Diptera. During the year much work had 

 been done on the flora of the islands, and the Committee re- 

 <|uired a grant of /'50 to aid in working out the collections 

 already made. (4) " The Biological Investigation of Oceanic 

 Islands." The Rev. T. S. Lea and the Rev. Canon Tristram 

 spoke of the important work being done by the Committee, 

 and of the necessity of its being done at once. 



Friday, Sepleiiiher 18. — The morning was devoted to a dis- 

 cussion on Neo-Lamarckism, Prof. C. Lloyd Morgan having 

 undertaken to open it. Prof. Morgan, after referring at some 

 length lo the precise positions taken up by Neo-Lamarckians 

 anil Neo- Darwinians, and the difficulty of disproving either 

 belief, said what was wanted was a really crucial case. If they 

 could in some way exclude natural selection in some cases, and 



NC. 1408, VOL. 54] 



allow it to act in others, they would obtain such crucial cases ; 

 and if the habit was equally transmitted, whether natural selec- 

 tion was present or not, that would present an exceedingly strong 

 point for the transmissionist. The nearest ajjproach to such a 

 crucial case, from his own observations, was the reaction of young 

 birds to water. There did not seem to be any instinctive re- 

 action to the sight of water, even on the part of ducklings. 

 But as .soon as the bill incidentally touched the water, the ap- 

 propriate drinking response was at once called forth. Why did 

 not a chick or duckling respond instinctively to the sight of 

 something so essential to its existence as water? He had very 

 little doubt that, under natural conditions, the mother bird 

 taught them to drink, and this implied that the presence of ihe 

 mother, as a source of instruclion, .shielded the young from the 

 incidence of natural selection. Now, though the mother could 

 lead her young chicks to peck at the water, she could not 

 suggest Ihe appropriate drinking response. In this matter she 

 did not shield them from the incidence of natural .selection, and 

 those which failed to respond to the stimulus would die of 

 thirst, and be eliminated. Thus, when natural selection was 

 excluded, the habit had not become congenitally linked with a 

 visual stimulus, and where natural selection was in operation 

 the habit had become congenitally linked with a touch or taste 

 stimulus. Prof. Morgan concluded by .saying that it was the 

 consideration of such ca.ses as the.se that had induced him to 

 take up the Weismannian position. In the di.scu.ssion. Prof. 

 C. S. Minot said he could not defend the Neo-Lamarckian 

 position, as the facts of embryology directly negatived it. Prof. 

 W. F. R. Weldon deplored a metaphysical treatment of the 

 subject. These matters could be proved or disproved by ob- 

 servation, and what they wanted were facts and not polemics. 

 Mr. F. A. Bather thought the Ammonites afforded at least 

 some proof of the Neo-Lamarckian doctrine. Prof. Ilarlog, 

 Dr. Hurst, Mr. McLachlan, Sir Henry Howorth, the Rev. 

 T. K. R. Stebbing, and Mr. E. W. McBride also took part in 

 the discussion. 



In the afternoon Mr. F. ICnock read a paper on "The Life- 

 History of the Tiger Beetle [Cicindela camfiestris).'' The bur- 

 rows of the larva, and how they were made, were described, and 

 the method which the larva adopted in order to catch its prey 

 was illustrated by some beautiful coloured lantern slides. The 

 various changes undergone by the larva to produce the perfect 

 insect were then outlined, and the method of egg-laying also 

 described. It was pointed out how perfectly the larva was 

 adapted to the conditions under which it lived, both in its 

 anatomy and habits. The author emphasised the importance of 

 studies of this character, and remarked that only very few of the 

 life-histories of these animals were known in any detail. After 

 this paper the Section adjourned to the loan museum, where a 

 series of slides of Eozobn was exhibited by Sir William Dawson. 

 The latter explained that upon the question of the organic or 

 inorganic character of these remains he had still an o|5en mind. 



Mr. J. W. Woodall gave an account of Dannevig's Flodevigen 

 hatchery for salt-water fish. This hatchery was erected in 1883, 

 with the object of ascertaining whether it was possible lo pro- 

 duce large numbers of the fry of the better class of sall-watei 

 fi.sh at a reasonable cost, the decrease in the fisheries, especially 

 the cod-fishing, having at that time been greatly felt. Diffi- 

 culties had all along been a considerable bar to the work, but 

 between the years 1890-96, i203millions of fry had been hatched 

 at a cost of o'd^d. per 1000, whilst last season the cost hadbeen 

 one-third of a penny per 1000, with, it w.as thought, a still further 

 chance of lowering the expenses. The hatchery cost .^800, and 

 the annual expenses were about ^^500. It was claimed that as a 

 result of the operations of this hatchery the cod was rapidly 

 increasing on the south coast of Norway, and especially at those 

 points where the fry had been liberated. In the discussion on 

 this paper. Dr. J. Hjort thought that ocean currents caused eilher 

 the destruction or the removal of a great number of the fry 

 liberated by the hatchery. The fry could not be kept sufliciently 

 long in the hatchery at a reasonable expense, and if liberated 

 before, the destruction of them must be very great. Prof. W. 

 F. R. Weldon concurred. He wanted more evidence as to the 

 survival of an appreciable number of the young animals when 

 cast into the sea. Mr. Walter Garstang thought it possible that 

 the supply of food fishes had been increased by means of fish- 

 hatcheries. The following two papers were then read: — "On 

 the necessity for a Fresh-water Zoological Station,'" by Mr. 

 Scourfield : and " On Improvements in Trawling Apparatus,'' 

 by Mr. J H. Maclure. 



