190 



SCIENCE 



[N. S. Vol. XXXVI. No. 919 



and the official Bureau des Longitudes took 

 the expedition under its motherly wing and 

 has now published the volume of which the 

 title is above cited. 



This expedition was scientific in its aims 

 and pole hunting formed no part of its pro- 

 gram. The staff comprised five members be- 

 side the leader, with a crew of fourteen; all 

 provinces of France were represented. 



The plan of the leader was, in brief, to take 

 up the work inaugurated by the Belgica ex- 

 pedition and extend it by explorations of the 

 southwest part of Graham Land, investigating 

 in all branches of science as well as geog- 

 raphy, so far as their personnel and equipment 

 would permit. 



This program was carried out in its main 

 features. The present volume includes an 

 introduction in which a brief resume of 

 previous researches in the same region is 

 given, after which the hydrography, tides, 

 chronometric record, pendulum observations 

 and the density and salinity of the seawater, 

 are discussed by Lieutenant Matha, atmos- 

 pheric electricity, meteorology and terrestrial 

 magnetism by Lieutenant Eey. The work is 

 carefully printed and the charts are of the 

 quality one expects from the bureau which 

 issues the volume. 



Wm. H. Dall 



SPECIAL AETICLBS 



A CASE OF SEX-LINKED INHERITANCE IN THE 



DOMESTIC PIGEON^ 



In breeding work with tumbler pigeons be- 

 gun at the Ehode Island Agricultural Experi- 

 ment Station some years ago a careful study 

 was made of the manner of inheritance of cer- 

 tain of the commoner colors of these birds, 

 especially black, dun, red, yellow, blue and 

 silver. This work was referred to in the 

 Twenty-first Annual Report of the Station, 

 1908, p. 301, and a full report of the results, 

 it is expected, will be published during the 

 present year. These experiments made clear 



' Contributions from the Laboratory of Experi- 

 mental Breeding, Wisconsin Agricultural Experi- 

 ment Station, No. 1. 



the fact that dun, yellow and silver are dilute 

 conditions of black, red and blue, respectively. 

 Indeed, this might have been surmised from 

 their appearance, but the fact was substan- 

 tiated by their behavior in the breeding tests. 

 As has been found in other animals, notably 

 in rabbits and mice, the dilute condition de- 

 pends upon a single factor, or more strictly 

 the absence of a factor, which produces the 

 effect upon whatever color it chances to be 

 associated with. In other words, " intense " 

 is dominant to " dilute," that is, if the factor 

 for the intense condition is present, the color 

 of the bird takes that appearance. This rela- 

 tionship, in the case of blue and silver, has 

 been pointed out by Bonhote and Smalley 

 (p. 603).= 



Although the earlier experiments showed 

 the general relationships of these characters, 

 it was only by the results of certain experi- 

 ments of the past year that the interesting 

 relationship of the intense and dilute condi- 

 tion to sex has come to light. No secondary 

 sex characters (in the ordinary sense) exist in 

 pigeons, and as a consequence there is no way 

 of determining the sex of the birds untU they 

 are old enough to reveal it by their behavior. 

 In the case of certain crosses made last year, 

 in which the male parent was a dilute (yellow 

 or dun) and the female a black baldhead,' 

 both black and dun offspring were produced, 

 and it became evident this spring that all the 

 blacks were males, while all the duns were 

 females. The following examples will serve 

 to illustrate. 

 Case I. 



Parents: t? 540 B, dun 



'$~647A, black baldhead. 

 Offspring: 790 A, black, (? 



790 B, black, c? 



847 A, dun, ? 



893 A, black, c? 



893 B, dun, ? 



954 A, dun, $ 

 ' Bonhote and Smalley, ' ' On Color and Color- 

 pattern Inheritance in Pigeons, ' ' Proc. Zool. Soc, 

 London, 1911, pp. 601-619, Pis. XXIII.-XXVL 



° In this discussion pattern is disregarded, since 

 it is due to independent factors with which we are 

 not at present concerned. 



