1904] 



KXOWT.l-PGI' c^- SCIENTIFIC NEWS. 



221 



other planes. Professor Newcomb m.ikes no hypothesis as to 

 the .ictiial thickness of stars in space, but considers only their 

 apparent distribution in the sky ; and the prol)lcin is thus 

 stated for mathematical discnssion : " Let us suppose a plane 

 taken at pleasure passing through our position in the universe, 

 which point we take as the origin of coordinates. This plane 

 will cut the celestial sphere in a great circle. The perpendi- 

 cular distance of a star from the plane will then be represented 

 by the sine of its distance from the great circle. Let us form 

 the sum of the squares of these sines for the whole system of 

 stars which we consider. The value of this sum will vary with 

 the position which we assign to the plane. The principal plane 

 of condensation, as I define it, is that for which the sum in 

 question is a minimum." The working out of these expressions 

 of condition gives a cubic equation whose three roots are the 

 three principal planes of the system of stars; the smallest root 

 corresponding to the plane of condensation, and the other 

 planes being at right angles to it. If the system of stars should 

 lie on a great circle then the value of the smallest root, corre- 

 sponding to the plane of condensation, will be iiero. In con- 

 sidering the galaxy a difficulty came up with regard to the 

 great bifurcation between Cygnus and Aquila, and Professor 

 Newcomb therefore considers two cases, one including the 

 branch in the galactic system, and one omitting it. In neither 

 of the two cases does he find that the central plane of the 

 galaxy is accurately a great circle in the sphere ; in other 

 words the solar system does not lie quite centrally within the 

 band of the Milky Way. Next Professor Newcomb considers 

 " The Belt," or band of bright stars which first -Sir John 

 Herschel and later Gould showed as lying on a great circle 

 which cut the plane of the galaxy at an angle of about 20". 

 Professor Newcomb shows indeed that this angle of deviation 

 from the plane of the galaxy is only about 11*.. from the con- 

 sideration of 36 of these bright stars which do not exhibit large 

 proper motion. Thirdly, he considers the plane of all stars to 

 mag. 2'5 ; of all stars to mag. y$ ; of all the lucid stars ; and 

 finally for the Wolf-Kayet or Fifth Type stars. The following 

 table gives the positions of the poles of these planes : — 



Galactic plane (omitting branch) 

 Galactic piano (including branch) 

 Gould's Belt, as found by Gould 

 The Belt, from 36 stars of small p.m 

 Plane of all stars to mag. 2-5 

 Plane of all stars to mag. 35 

 Plane of all lucid stars 

 Plane of the fifth type stars 



From a consideration of the richness of the galactic region, 

 Professor Newcomb concludes that if the galactic agglomera- 

 tions were excluded from consideration, the crowding of the 

 lucid stars towards their principal plane would be scarcely, if 

 at all, greater than what we might expect as the result of the 

 irregularity of chance distribution, and that we should still find 

 a continuous increase in the richness of the sky from the poles 

 to the galactic circle, where it would probably be nearly twice 

 as great as at the poles. 



BOTANICAL. 



Though the ovary of the oak (Qiunus) is usually more or 

 less perfectly three-celled, and each cell contains two ovules, 

 the mature fruit, known to everybody as the acorn, nearly 

 always contains only one seed, and therefore produces only 

 one seedling. Professor Coker, in the January number of the 

 Botanical Gazette, refers to acorns which invariably contain 

 two or three seeds, and one is illustrated giving rise to three 

 vigorous seedlings. These acorns were produced by a rock 

 chestnut oak {Qucrcus pniiiis), found near Baltimore, Mary- 

 land. The same writer has met with a two-seeded aconi of 

 O. vdutina, but in this instance the other acorns of the same 

 tree were one-seeded. 



Professor Coker also has an interesting note in the same 

 publication on " Spore Distribution in Liverworts." He alludes 

 to the fact that terrestrial species usually have their capsules 

 raised on elongated stalks, while in the case of those that grow 



on trees the stalk of the capsule is seldom long, as in the 

 latter the position of the plants some dist.incc' above tlic 

 ground ensures the distribution of the spores on the dehis- 

 cence of the capsules. He sliows, however, that in Poiilla 

 platyphylhi, though the vegetative shoots arc closely ad- 

 pressed to the bark of the tree, the fertile ones, just before 

 the ripening of the spores, bend away from it and often 

 project .a centimetre or more. In consequence of this the 

 spores get more exposure to winds, which prevent their fall- 

 ing and remaining amongst the leavers of the parent plant. 



In recent volumes of the CmiiptiS Riiuliis, Monsieur G. 

 Bonnier has some interesting and important papers giving the 

 methods and results of his cultural experiments on plants in 

 the Mediterranean region, with a view to the modifications of 

 their anatomical structure. The experiments have been 

 carried on at Toulon, and at Fontainebleau, thirty-seven miles 

 S.S.K. of Paris. Fifty peremiial species were selected, each 

 of which was split into two portions, one for cultivation at 

 Toulon, the other at Fontainebleau. The plants were pro- 

 cured from the latter place, and the soil in which both sets 

 were cultivated from Toulon. The results obtained are very 

 interesting. Toulon has a less uniform climate than h"on- 

 tainebleau, and is drier in sununer, conditions which would 

 be expected to le.id to some modifications of the infernal 

 structure of the stems and leaves. The plants grown at 

 Toulon have acquired the same peculiarities of anatomical 

 structure as those of the plants of the same species found 

 growing wild in that locality. The annual ring of wood was 

 thicker and contained vessels of a larger calibre, while the leaf 

 characters were more xerophytic than in the Fontainebleau 

 specimens. Instances of remarkable variations in size and 

 habit of plants grown in different latitudes and at different 

 elevations are familiar to most botanists, and an extensive 

 knowledge of such variations is most important to the systema- 

 tist, who is often perplexed in determining whether characters 

 with which he has to deal are of specific value, or whether 

 they merely represent the influence of local conditions. 



'S^^rrrs- 



ORNITHOLOGICAL. 



Bv W. P. PvcK,«T, .V.L.S,, F.Z.S., M.B.O.U., &c. 



InfaLnticide by a Meadow Pipit. 



Lord Balfourof BuRLEicH,inaletterto the Fitld for July 16, 

 describes, on the authority of his keeper, how a meadow-pipit 

 ejected its own young from the nest in favour of a young 

 cuckoo. 



The foundling, it appears, emerged from the shell some forty- 

 eight hours after the first of the young pipits, but a few hours 

 later the pipit was found outside the nest. Knowing nothing 

 of the evil reputation of young cuckoos he replaced the nest- 

 ling and watched for the hatching of the remaining eggs. 

 This took place a few hours later, and he then saw what he 

 believed to be the hen bird " remove first one and then the 

 other and deposit her own offspring outside her home. Not 

 being yet satisfied, he put two of the young ones back into the 

 nest, and to avoid possibility of mistake watched operations a 

 second time. He again saw the unnatural mother eject her 

 own young in favour of the stranger. The young cuckoo was 

 fed and tended by both titlarks and a few days after left the 

 nest." 



This account is certainly of extreme interest and is probably 

 unique. There can be no doubt about the fact that norm.dly 

 the young cuckoo performs the work of eviction. Indeed, 

 according to most observers, this little monster is specially 

 endowed by Nature with a hollow back into wliich the victims 

 are forced by the wings and held there till the edge of the nest 

 is reached, when they are toppled over. Concerning this 

 hollow back we shall have something to say later. 



This letter was followed by another (July 23) from a corre- 

 spondent who, after reading Lord Balfour's letter and finding 

 dead wagtails outside the nest, came to the conclusion that 



