April, 1903.] 



KNOWLEDGE 



85 



the south of Engird, or in sheltered lowlands near the 

 coast. During October and November too there is a 

 passage of Lapwings from Northern Britain to Ireland. 



Autumn Immigration from North- Western Europe. — 

 Arrivals of Lajiwings from Scandinavia occur throughout 

 October and the early part of November, but in no great 

 numbers. 



Autumn Immigration from the East. — The records, 

 although meagre, are sufficient to leave little doubt that 

 immigrants from the Continent — occasionally in consider- 

 able numbers — arrive on our east coast by a direct passage 

 across the southern waters of the North Sea. This immi- 

 gration is renewed during severe winters on the Continent. 



Autumn Passage of Im.migrants. — -Lapwings, it seems, 

 do not use our coasts — as so many other birds do — 

 as a mere highway on their passage north and south to 

 other countries. 



Autumn E migration from Britain. — Our native 

 Lapwings and the autumnal visitors from the Continent 

 seem loth to quit our shores. No Lapwings have been 

 detected crossing the Channel before November, when the 

 approach of winter constrains some of them to seek more 

 genial climes. 



Winter Movements and Emigration. — These are con- 

 trolled by, and vary with, the climatic conditions of the 

 season, and their extent is proportional to its severity. 

 Heavy snow and severe frost cause great movements south- 

 wards along the coast and overland. Should such 

 conditions extend to the South of England, much emigra- 

 tion is embarked ujjon for the shores of Prance. Devon, 

 Cornwall, and the Scilly Isles, as well as Ireland, are also 

 much resorted to during severe frosts and snowstorms. 

 It is when thus retreating before adverse conditions that 

 the movements of the Lapwing become pronounced and 

 widesjiread, and, in this respect, contrast markedly with 

 the other migrations of this species. On these occasions, 

 too, the bird chiefly approaches the light-stations. Com- 

 paratively few perish by starvation. 



Spring Movements from British Winter to Summer 

 Haunts. — Occasionally earlier, but usually towards the 

 end of February and early in March, the Lapwings 

 gradually return to their breeding haunts in Britain. 



Spring Immigration from Southern Europe. — The 

 Lapwings that have left England for the south appear to 

 return across the Channel towards the end of March. 



Spring Passage Northward and Emigration to Northern 

 Europe. — During March and until mid-April the return 

 migration northward of the Lajiwings proceeds in a 

 somewhat leisurely fashion. The emigrants for North- 

 west Europe mainly move along the east coast. Those 

 that have wintered in Ireland generally depart from the 

 north-east coast and proceed in various directions towards 

 iScotland. No return passage in spring of Lapwings 

 across the south of the North Sea to Central Eurojx! has 

 been noticed, but as these birds move by night, and are 

 seldom attracted by the lights, there is great difficulty in 

 observing small movements. 



The Status of the Ooldfinch in Britain (Zoologist, January, 1903, 

 pp. 23-2()j. — Mr. J. A. HarvielSrown here gives brief exiracts from 

 various authors to show the status of tho Goldfinch in many counties. 

 It is ])ro|)o8od to bring the inforniatiim up t« date, and to complete 

 it as far as possible with the eo-ojjeration of diiferent observers. 



Bidioer'.i Petrel in Sussex. — At the February meeting of the 

 liritish Ornithologists' Club, Mr. J. L. Bonhoto recorded that a 

 specimen of this bii-d was ]iicked up dead near Beachy Head, ou 

 February I'rd last. 1?u1\vim''» Petrel breeds in the Canaries and 

 Madeiras, as well as iu seme islands in the Pacific. It has been known 

 to occur oidy once before in (Ireat Britain, viz., in Yorkshire in 1837. 



All contributions to the column, either in the wai/ ol' notes 

 or photogrnplis, should be forwarded to Harry F. Withkrby, 

 at the Ofjirr f)/ Knowledge, 326, High Holhorn, London. 



Astronomical. — A variable star, with a period shorter 

 than that of any variable previously known, has been lately 

 discovered in the course of the photometric work at Pots- 

 dam. The period is 4h. Om. 13s., and the range of varia- 

 tion from mag. 79 to 86. Changes of magnitude go on 

 continuously throughout the period, so that the variability 

 is not of the simple Algol type. The star is B.D.4- 56° 

 No. 1400, R.A. 9h. 36m. 44s., Decl.-I- 56° 24'-6. 



In a discussion of his photographs of the spectrum of 

 the chromosphere taken during the eclipse of 1900, Mr. 

 Evershed confirms the conclusion, arrived at previously by 

 Sir Norman Lockyer, that the lines of a metal which are 

 exceptionally strong are in most cases lines which are 

 enhanced in the spark spectrum. In explanation of the 

 predominances of these lines throughout the whole depth 

 of the chromosphere, and their relative absence from the 

 Fraunhofer spectrum, it is suggested that the entire 

 chromosphere consists of small eruptions of the nature of 

 metallic prominences or jets of highly-heated gases, the ! 

 ascending hot gases giving the predominant features to / 

 the flash spectrum, while the Fraunhofer spectrum repre- \ 

 sents the absorption of the ci)oler descending gases only. '; 



Dr. Chree, of the National Physical Laboratory, finds ', 

 that the equinoxes are the seasons at which the amplitude 

 of the diurnal inequality of terrestrial magnetism, when 

 considered absolutely, is most dependent upon sunspot 

 frequency ; and that winter is the season when sunspot 

 frequency is most influential relatively to the total range. 



Sir Norman and Dr. Lockyer findiifrom a discussion of 

 prominence observation^that the variations of the general 

 terrestrial magnetic pnenomena synchronise with the 

 occurrence of prominences about the solar equator (the 

 periodicity of which appears to agree very closely with 

 that of the spots), while the " great" magnetic disturbances 

 accompany the outburst of prominences in the polar q 

 regions of the sun. This may explain why magnetic / 

 storms sometimes occur when no large spot is visible. — A.F. ., 



Botanical. — One of the most remarkable among 

 amphicarpous plants is Cardamine chenopodifolia, which 

 has recently been the subject of a paper by Dr. E. P. 

 Wright in Notes from the Botanical School of Trinity 

 College, Dublin. Thi.i interesting Crucifer is a native of 

 various parts of South America, from Brazil to Argentina 

 and the Island of Juan Fernandez. It produces an aerial 

 raceme of small flowers, which are succeeded by seed-pods 

 similar to those of the British C impatieiwt. They are 

 usually many-seeded and dehisce elastically, scattering 

 the seeds to some distance. But in addition to the aerial 

 flowers and fruits, others are produced at the base of the 

 plant. The flowers are cleistogamous, extremely minute, 

 without petals, and are borne separately at the tip of sub- 

 terranean peduncles. The fruit is short and thick, two- 

 celled, and contains one large seed in each cell. This is 

 probably tho only amphicarpous CrucLfer, but at least two 

 other plants of the order are known which mature their 

 fruit underground, namely, Morisia hypogma, a native of 

 Corsica and Sardinia, and Gcococcus pusillus, a miniature 

 plant from Western Australia. The former grows in the 

 Rock Garden at Kew. The fruits in both these develop 

 much in the same way as those of the Earth-nut, Arachis 

 hypogx.a. Amphicarpous plants are found in various 

 natural orders, some particularly interesting ones being 

 discussed in a paper bv Dr. Lindmaii in the Ofversigf K. 

 Vet.-Akad. Fdrhandl., Stockholm, for 1900. 



Sir J. D Hooker's biography of his father, Sir W. J. 

 Hooker, appeared iu the December number of the Annals 

 of Botany, and is worth perusal by the general reader as 



