54 CHARLES E. STOCKABD 



similar allels are present in homozygous state. A single litter 

 of seven F2 animals shown in plate 2 illustrates these facts. 

 Two animals (figs. 5 and 6) are homozygous for short legs; 

 two (figs. 10 and 11) are homozygous for long legs; and three 

 (figs. 7, 8 and 9) are heterozygous for leg length, carrying 

 the allels for both short and long, and are therefore inter- 

 mediate in length. This single litter group presents the 

 1 :2 :1 ratio as nearly as is possible with seven members ; one 

 intermediate leg-length is lacking. 



The skeletons from three generations of this cross are seen 

 in plate 3, the contrasted parent skeletons at the top (figs. 

 1, 2 and 3), the middle line showing the F x hybrids (figs. 4, 5 

 and 6) and the bottom row (figs. 7-11) illustrating the three 

 degrees of leg length in F2 skeletons. 



A number of other contrasted characters from the parent 

 stocks are redistributed and often occur in new combinations 

 among the F2 hybrids. The recessive tricolor spotting of 

 the bassethound reappears in some of both the short and 

 long legged animals, and the shepherd color and pattern 

 predominate in both leg types, as is illustrated in plate 4. 

 There is no linkage between coat texture and color pattern 

 and leg length. In fact, dogs, with their large number of 

 chromosomes, have not yet definitely yielded a linkage among 

 the single factor characters studied. There are apparent 

 correlations and associations between some conditions and 

 certain elements in multiple factor complexes, but few of 

 these are clearly marked. The erect position of the ears of 

 the shepherd is complex in inheritance and not one of the 



PLATE 3 



EXPLANATION OF FIGURES 



Skeletons of the cross between the German shepherd and bassethound showing 

 contrast in leg length and form in the pure breeds and the resulting condition in 

 the first and second generation hybrids. 



1-2 German shepherd 111?. 4-5 F, 124^. 



3 Bassethound 214$. 6 F, 123^ (brother of 



7-11 Three members of a litter of eight F 2 hybrids. 

 7-8 404 <?. 9 and 11 402 $. 10 403 <?. 



