January 1. 1901 ] 



KNOWLEDGE. 



to shoot the birds to establish their sexual identilu-atiou, 

 but without that one might fairly assume that here was 

 an instance of winier-love. A few days later, in another 

 district. 1 saw two wrens behaving in a precisely similar 

 manner. The incident is, indeed, a common one. 

 lu autumn the hidge sparrows seem to be choosing mates 

 for the winter aiid next year, for we see. a silent and 

 timid one pursued by one or more twittering and flutter- 

 ing others, ajid ai-o able easily to recognise a study in 

 the art of love, as the gentler birds imdei-stand it. At 

 that time the male house sparrows have recommenced 

 their mobbing of their much-worried female relations, 

 and throughout the winter pairs of this species sleep in 

 accustomed shelters. The great titmouse seems to have 

 selected his mate before Christmas, at which time the 

 birds are generallv travelling in couples, though often 

 two couples aie in the same resort. This is in keeping 

 with tlie resumption of the bird's clinking song-note in 

 autumn. Nuthatches likewise are generally found in 

 couples, before the cold weather has commenced, and, 

 throughout it, owls may be heard hooting and calling. 



Although the finches and allied birds do not generally 

 sing in tBe cold, ouo cannot say tliat attachments 

 between the sexes do not then exist — except, perhaps, 

 in the case of the bachelor chaffinch. The male bull- 

 finch is generally accompanied by his mate, and if 

 either is disturbed it does not retreat without calling 

 the other. Even the grecnlinch, gregarious as he is in 

 winter, seems sometimes then to travel in couples. In 

 the severe winter of 1894-5 I killed some fifty gi'cen- 

 finches in a garden, to supply the huder of a kestrel 

 which seemed to be worth the sacrifice; and I soon 

 noticed that the successive finches appeared in pairs, or 

 in small groups of even number. Only once or twice 

 was an odd number of them there. The attraction was 

 some loose straw, and the trap a spring-net, which could 

 be released as desired. Directly after a pair of the birds 

 had met their fate another pair appeared, and finally 

 a couple nested in the garden, as usual. 



At the moment of writing (early in December) I have 

 been watching the amorous auties of four couples of 

 jackdaws, each couple keeping aloof from the others, 

 though all were in the same spot. Most of them were 

 gaiTulous as usual; and, in flight, a leading bii'd would 

 sometimes descend on drooped wings, uttering meanwhile 

 the long rough '' carr,' which seems to be the love-note 

 of the species. But two of them, perched high in an 

 elm, were actually preening or pecking each other's 

 feathers in a gentle manner. I have never before seen 

 other birds than pigeons do this, and then only at 

 nesting-time, but through a telescope (xll dia.) the 

 movements of the birds were clearly visible. 



The rook, however, seems to furnish the strongest 

 instance of affection in. the dead season. My brother, 

 Mr. E. X. Witchell, who sometimes resides near Min- 

 chinhampton Down, has often in winter seen one of the 

 rooks which abound there take to another some moi'sel 

 of food. Quite recently he saw a rook take up some- 

 thing, hop away to another rook, and give up the prize, 

 which the receiver ate. The rook has as good an appe- 

 tite as any other bird, and such an in.stance as this is 

 proof of a bond between the birds higher than mere 

 mutual association for detecting danger, or preferential 

 companionship. Many of us are seemingly too ready 

 to estimate bird-love at the level of the poultry-yard, or 

 at any rate to consider it as incidental to springtime 

 only. In several species this estimate seems to be 

 supported by fact; but in others "love" seems to be 

 of a more enduring and a nobler kind. 



AsTKONOMicAi. — From spcotroscopic oliservalions, Mr. 

 Newall has found that the velocity of a, Persci is variable, 

 with a period of possibly four or sixteen days. Presumably, 

 therefore, this is another star which has a relatively dark 

 com]nniimi. Such systems, as pointed out by Prof. 

 Campbell some time ago, are probably at least as plentiful 

 as visual binaries. 



A si;e<:ial interest attaches to the spectroscopic binary 

 Capella, indeiiendently discovered by Mr. Newall and 

 Prof. Camjtbell, for the reason that the companion is 

 sufficiently luminous to show a sjn'ctrum, and the com- 

 putatious suggested that the components might ije 

 separated visually in a powerful ti'lescope. With tho 

 ■28-inch refractor at Greenwich, an "elongation" of the 

 star, amounting to at least a tenth of a second, has 

 been observed, iu accordance with the spectroscopic observa- 

 tions, but Prof. Hussey, observing with powers U]i to 

 2600 on the. Lick refractor, has failed to find either 

 elongation or separation. 



As a result of measurements of one of the charts 

 alreadv published in heliogravure by the Freueh observa- 

 tories taking part in the International Astrograjihic C'liart 

 of the Heavens, Prof. Turner I-onsiders it prol able that 

 they yield star places at least as good as those obtained 

 witii meridian instruments. It appears, however, that 

 the complete results, if produced iu the same careful 

 manner, would cost each of the eighteen participating 

 observatories no less than =£10,000. 



M. Deslandres, of Meudon, believes that he has succeedi'd 

 in registering, Ijy means of the infra-red rays, the general 

 form of the solar corona without an eclipse. 'J he eclipse 

 results on which his method is b^scd, however, appear to be 

 at variance with those obtained by Prof. Langley. — A. F. 



Botanical. — A caoutchouc-prod ucing plant, which gives 

 promise of thriving under cultivation, unprotected, iu a 

 temperate climate, is now, according to the Bevue des 

 CuUures CoJoniales, engaging the attention of the officers 

 of the Jardin Colonial at Viuceunes, near Paris. This 

 plant, Encominin iilmoides, has been for some time an 

 object of considerable interest to botanists, an interest 

 increased in consecjueuce of its bark being highly esteemed 

 by the Chinese as a touic medicine. Its first appearance 

 ill this country, about ten years ago, was due to Dr. A. 

 Henry, who sent specimens from Hupeh, China. Shortly 

 after it was described and figured in Hooker's Tconns 

 Plantarum. An elastic gum-like sul stance, abundantly 

 present in almost every part of the plant, formed the 

 subject of an important jmper by Professor Weiss in the 

 Transactions of the Linnean Society. The French propose 

 to introduce the Eucommia into Anara, Touquiu, and 

 their colonies in North Africa. 



Instances of variation from the normal opposite or 

 whorled arrangement of the leaves in Labiatse, e.xcluding 

 such as would be considered in a work on plant teratology, 

 are exceedingly few. Their existence, however, has formed 

 the subject of a paper, which Messrs. Burkill and Wright 

 have contrilmted to the last volume of the Journal of the 

 Linnnan Society. About four years ago.aFrench botanist, 

 M. Hua, established the genus Icomum on a tropical 



