May 3, 1906J 



NA TURE 



13 



worked up as it uccuiTL-d a hundred years before the 

 tirth of Herodotus ; its evidence, whether for or against, 

 is held to be inadmissible. 



A confirmation of these results is supplied by the 

 lunar eclipses of the Almagest. On working- them up, 

 it is found that the residuals are so large as to show 

 that they arc entitled to far less weight than the solar 

 eclipses. Their value lies in the fact that the separate 

 delcrminalions from the lunar eclipses group them- 

 selves round the values derivi'd from solar eclipses. 

 The lun:ir eclipses are given in Monthly Notices, Ixvi., 

 jjp. 6-7 ; they are nineteen in number, and in only 

 ten cases is a numerical estimate of the magnitude 

 recorded. These ten cases .alone therefore test the 

 newly-discovered fact which, in language that becomes 

 .•i[)propriate only if the second section of results is 

 admitted, states that the earth's orbital motion is sub- 

 ject to a secular acceleration of 4". Now of the ten 

 lunar eclipses available, seven give accelerations lying 

 between 2" and 6". It is therefore hard to believe 

 that zero and not 4" is the correct value. The times 

 «f the lunar eclipses are equally striking in their con- 

 firmation of the result. Nearly thirty years ago a 

 correction was introduced into Hansen's Tables based 

 upon these eclipses. The main question is one of 

 <;vidence. It is no use to point out in the third section 

 of this paper how certain chang;es may be accounted 

 for, if they are not shown to exist. On the other 

 hand, no objections to a particular explanation of the 

 physical reason can weaken the case for the observed 

 fact that these changes are taking place. What is 

 sufficient evidence? Two eclipses would suffice, if 

 they had been described with a wealth of detail that 

 established complete confidence in the records. A 

 hundred eclipses of the actual sort would probably 

 satisfy the most sceptical, even though the place 

 assigned were always " tacitly assumed (to be) the 

 capital where the record was made, or the place where 

 the poet or historian lived." The smaller number of 

 eclipses, which it has alone been possible to produce, 

 should suffice to make a case almost if not completely 

 amounting to certainty. P. H. Cowell. 



VARIATIONS OF DOMESTIC POVLTR'Y.' 



THE book under notice is one of an original 

 character. It is an attempt to describe all the 

 different races of domestic poultry that exist in 

 various parts of the world, and as such is not without 

 its value, as it gives us a description of the races of 

 fowls as they exist, not only in Asia, but in the 

 various States of Europe and the United States of 

 America. Tlie book treats almost solely of the races 

 of fowls from a fancier's point of view. The plumage 

 and external characters which would be noticed in a 

 show-pen are those that are dwelt upon, and as a 

 scientific treatise the work cannot be regarded as 

 having any special value, and would be unfairly 

 treated if it were regarded from the same standpoint 

 as Darwin's " Variation of Animals under Domesti- 

 cation." 



The illustrations, which are very numerous, are 

 not original, but taken from the fancy poultrv 

 journals, where the birds are drawn with the usual 

 exaggeration of the points valued by the fancier, and 

 bred for securing prizes. The consequence is that 

 some of them are good and others quite the reverse, 

 but the plumage in many is exaggerated. To scien- 

 tific ornithologists this history of the location of colour 

 in the different parts of the plumage of birds, and the 



1 "Races of Domestic Poultry." By Edward Brown. Pp. xi-i-234 ; 

 illustrated. (London : Edward Arnold, 1906.) Price 6s. net. 



fixture of the patterns in the races, is one of consider- 

 able interest. To those acquainted with the details 

 of poultry breeding it is well known that any vari- 

 ation of the colour or texture of feathers which 

 appears in any particular specimen can, by careful 

 selection of the offspring, for a series of generations, 

 be readily perpetuated, and by crossing with other 

 varieties almost any pattern or disposition of colour 

 can be obtained, and what is called a new breed 

 formed. This is illustrated by the engraving, which 

 we borrow from the work, of a German race at pre- 

 sent but little known in this country, called the Laken- 

 fclder. In this the colours are transposed from their 

 general position, and a remarkable looking fowl is 

 produced, which is correctly represented in the 

 engraving. 



It is of much scientific interest to trace the extent 

 of the variation which can be induced by careful 

 breeding. In the fowl, these variations have been 

 almost exclusively confined to the plumage, which in 

 some instances has been increased to an enormous 

 extent, as in the production of quill feathers 8 inches 

 long on the feet of the show Cochin, and the general 



r^jtar 



Fig. I. — Lakenfelders. From "Races of Domestic Poultry." 



increase of the plumage to a great extent, so that 

 the modern show Cochin does not at all resemble 

 the original birds brought from Shanghai. In other 

 cases the plumage has been partially abolished, as 

 in the Nackthalse or Transylvanian naked necks, in 

 which the head and neck are entirely denuded of 

 feathers, and the skin assumes the red colour of the 

 comb. These variations are permanent, and are 

 intensified by long-continued breeding. The produc- 

 tion of spangles or dark markings at the end of the 

 feathers, of bordered margins of black on a light 

 ground in the whole of the body feathers, and of 

 regular transverse bars across each feather of the 

 plumage, have all been accomplished and perpetuated 

 by careful selection. 



The various breeds of ducks, geese, and turkeys are 

 also treated of. 



The work contains in an appendix a very elaborate 

 and useful list of the names of the races in all the 

 European languages, which will prove of great value 

 to all investigating the subject of variation. 



W. B. Tegetmeier. 



NO. 1905, VOL. 74] 



