investigators tho object of especial study and, among these characters, 

 that of barring has received some consideration. We may therefore 

 review briefly some of the recent work on this subject. 



n. Historical Resume. 



Hurst (1905) was among the first to test the Mendelian principles 

 of heredity with respect to characters of fowl. .\lt hough he did not 

 11 Hike a particular study of barring he makes several references to the 

 iil)peiirance of this color-pattern in cross-bred birds. .Vmong other 

 crosses was Houdan cf X White leghorn 9 . This cross "gave 94 

 whites and 11 blacks; of these, 22 were apjwirently clear white, 72 

 \vhit(* ticked with black, one black with white head, and 10 black 

 tick(<l with wiiite. In each case the tickings were slight ami not 

 ext<'nsive, so that in the grouncl color, the distinction l>etween white 

 and i)lack wius marked and di.scontinuous. In the first plumage all 

 except two of the clear whites develojx^fl black ticks, similar to those 

 that were born ticke<l; the blacks <levelope<l into blacks and 5 

 'cuckoos;' 5 of the blacks were .slightly ticket! with white in the 

 crest only, and in their plumage were indistinguishable from the 

 f 'r6ve-c(rur brec^l, the other black <leveloi>e<l into a typical light 

 Houdan; the 5 cuckoos were gray-white, barrc^l with blue-black or 

 white feathers; both the blacks and the cuckoos were distinctly 

 shaded with brown. Curiously enough the 6 blacks were all pullets 

 Mild the 5 cuckoos all cockerels!'* Hut this result, as will Ix* shown 

 later, is wholly explainable on the groun<l that Hurst's White Leghorn 

 99 were heterozygous for the barred plumage character, and that 

 they were not pure for white. 



Later, Hurst mated one of the cuckoo cockerels willi iwn of the 

 black pullets. From this mating, 43 chicks were hatched, all with 

 black down-feathers. Hut 34 were tickefl with white, 7 had white 

 1 leads and 2 were strongly shade<l gray. Of those hatchefl, 31 were 

 reared and gave, in the first plumj\ge, 17 cuckoos and 14 blacks. 

 "Of the cuck(K)s, 7 w«rr »M>f]<<T«'K- and 10 \vrr«^ pidlc»ts. and of the 



