December 9, 1920] 



NATURE 



487 



tion which is accompanied by seasonal on-shore and 

 off-shore movements. But the periodic migrations of 

 the species are markedly interrupted when the call 

 of maturity comes. Then the migration is contra- 

 natant, a longer or shorter distance according to 

 species and circumstances, due to the effects of on 

 internal secretion or hormone which exercises a pro- 

 found influence on the central nervous system, and 

 may also produce somatogenic results. The only 

 invertebrate which is definitely known to react in 

 this wav on the approach of spawning is the crab — 

 the females migrate contranatantly at that period — 

 but it may be presumed that other large, active 

 Crustacea and Cephaloooda respond similarly. Prof. 

 Meek referred to .Amphibia as being similarly affected 

 at the spawning season, the hormone bringing about 

 a return to grecariousness as well as somatogenetic 

 effects which characterised the period. The same 

 appears to be true of aquatic reptiles, birds, _ and 

 mammals, and Prof. Meek 'su£'t?este<l that this pointed 

 a wav of approach to the subject of aerial mi/<ration. 

 In the discussion following. Prof. I.lovd Mordan 

 directed attention to the breedincr habits of lapwintjs, 

 .nnd supfested that thev were to be explained as due 

 to hormone action, and other sneakers proposed that 

 attempts should be made to isolate and experiment 

 with the hormone. Prof. Garstang discussed the 

 Question with reference to plaice, and Prof. Nfeek 

 rf-piied, pointing out in this case the distinction 

 between the periodical and the spawning migrations. 



Emhryological Studies. 



Prof. J. E. Duerden gave an account of the pineal 

 eve of the ostrich (for a summary of this paper see 

 Nature, vol. cv., pp. 516-17), described a caudal 

 vesicle in ostrich embryos, and recorded the presence 

 of Reissner's fibre. In embryos of about ten days' 

 incubation a prominent vesicular swelling is present 

 :it the tip of the tail or on the dorsal surface near 

 the tip. The cavity of the vesicle, in which the 

 central canal of the spinal cord terminates, varies 

 much in size and shape in different specimens. The 

 ventral wall of the spinal cord lines the floor of the 

 1 avitv and terminates somewhat abruptly, and the 

 • lorsal wall of the cord merges gradually into the 

 mesenchymal tissue which constitutes the dorsal and 

 lateral walls of the vesicle, without, however, show- 

 ing any differentiation into an epithelial laver. The 

 lavitv is filled with a coagulable fluid in which cellular 

 tissue in process of degeneration frequently occurs, 

 and occasionally much black pigment is present. The 

 f'Xternal enlargement persists for only a short time, 

 rarely lasting after the twentieth day of incubation. 

 .■\ similar vesicle has been found in several reptiles, 

 and is well-developed in the penguin and the puflin, 

 though in these it is not so large as in the ostrich. 

 It is suggested that the vesicle in the ostrich, which 

 varies so much in size, is in some way concerned with 

 the regulation of pressure of the cerebro-spinal fluid 

 .it this early stage. Longitudinal sections of the 

 caudal region show the presence of Reissner's fibre 

 and its posterior attachment to the mesenchymal 

 tissue. Reissner's fibre has been found to occur 

 within the central canal of the spinal cord of verte- 

 brates from the rvclostomes to the primates. 



Mr. J. H. I.lovd dealt with the early development 

 of the pronephros in Scyllium and Chr>'semys, and 

 supported Mr. Burlend's view that the pronephros 

 .Trises as a non-segmental groo\'e from the som.itic 

 laver of the mesoblast, and that the anterior portion 

 of the duct is formed bv constriction from this groove, 

 and not by fu«ion of the distal ends of tubules. The 

 evidence, as presented by the illustrations, was not 

 convincing, and was subjected to coniiidcrab'e 

 criticism. 



\n ?rifi7 vor TOf^l 



The Movements of the Sea. 

 At a joint meeting of Sections D and E, Dr. E. C. 

 Jee gave a paper on the movements of the sea. He 

 pointed out that the temperature of the deep waters 

 surrounding the British Isles is essentially due to 

 the Atlantic circulation. He dealt in some detail 

 with the northern North Sea current, and stated 

 that no significant correlation has yet been demon- 

 strated between the variations of this current and 

 fluctuations in the landings of fish. The current 

 which enters the English Channel from the Atlantic 

 affects the fisheries of the south-west area, and i;s 

 strength seems to show the following variations : .\ 

 winter maximum and a summer minimum, and a two- 

 year, a six-year, and a twelve-year periodicity. It is 

 probable that the fluctuations in the landings of pil- 

 chards are correlated with the variations in strength 

 of. the Channel current. The periodicities referred to 

 are now being investigated by the International 

 Council. The examination of numerous samples of 

 sea-water and the liberation of surface and bottom 

 drift-bottles are being undertaken with the object of 

 obtaining information for a study of the migrations 

 of mature plaice to and from their spawning-grounds 

 in the Flemish Bight and the probable drift of the 

 pelagic plaice eggs and the location of the fry in their 

 various stages of development. 



Prof. R. B. Poulton gave a preliminary account of 

 the hereditary transmission of a minute, extremely 

 variable, and generally asymmetrical marking in tl ? 

 forewing of the currant moth (Abraxas grossulariata). 



J. H. ASHWORTJI. 



University and Educational Intelligence. 



BtRMiNGii.'VM. — At the last meeting of the council 

 the Principal reported that the Staffordshire Educa- 

 tion Committee is increasing its grant to the Uni- 

 versity from 450I. to 1000/. per annum. The Wor- 

 cestershire County Council recently increased it^ 

 annual contribution from 300/. to 500J. ; and the 

 Dudley Town Council has informed the University 

 that it will include an annual sum of 50!. in its 

 estimates. 



Messrs. Dorman and Co., of Stafford, have pre- 

 sented a 20-h.p. petrol engine, and Messrs. Sturge 

 and Co. an old beam engine. The Pro-Vice-Chan- 

 cellor, .Alderman Clayton, is providing lool. towards 

 the cost of removal and re-erection of the latter. 



The University is affording facilities in the depart- 

 ment of pathology to enable Prof. Shaw Dunn to 

 take part in the training of the Naval and R..A.M.C. 

 personnel reauired for the physiological department of 

 the Chemical Warfare .Section at Porton. 



Mr. R. W. W. Sanderson has been appointed a 

 demonstrator in phvsics for the current session. 



Mr. R. O. .Abrahams has been apjwinted honorary 

 assistant cur.ntor of the pathological museum, Section 

 of .Surgery. 



Cambriogb. — By the time that this ismu- .11 

 the vote on the admission of women to memli 

 of the University will have taken place. Both >ni.-~ 

 are hopeful of the issue, and a fairly close vote is 

 generally anticipated. Something of the vigour of 

 the earlier fighting on this question has vanished, 

 perhaps becau.se the "old guard" realise that thev 

 are fighting a losing battle. If they hold their nrivi- 

 legefl position this tiine thev know that their flanks 

 are in the air, and that It is only a short time before 

 they are liable to be overwhelmed in an attack from 

 another quarter. .Somewhat late in the dnv, mnnv 

 of them arc holding out a promise of a pinre where 

 everybo<ly may go if only the .Senate will throw out 



