78 CHARLES R. STOCKARD 



fication shortens such bone to a lesser degree than either 

 shepherd typed or bassethound typed bone. The constitution 

 of the bone itself is of consequence in determining the degree 

 of shortening from chondrodystrophy. This fact must be 

 taken into account when diagnosing an individual as gen- 

 etically mixed si or pure ss for the achondroplasic condition. 

 The above facts are somewhat better illustrated by the 

 photographs in plate 12. The two dogs in figure 1 are brothers. 

 No. 1214 $ at the left carries the homozygous condition, ss, 

 for achondroplasia and has, in addition, inherited the factors 

 for the slender typed Saluki bone; while a brother, 12115, 

 also homozygous, ss, for leg length, has inherited almost pure 

 bassethound quality bone and consequently shows stockier 

 legs, larger, more outspread feet with more pronounced ab- 

 duction at the wrist, and finally a much lower swung body. 

 Figure 2 in plate 12 shows two brothers from a different lit- 

 ter. These again are both homozygous, ss, for the achondro- 

 plasic short extremities. Judging from its development and 

 bone type, the animal on the left, 1441 $ , has inherited almost 

 pure Saluki bone quality. The brother, 1439 $ , at the right 

 presents a most exaggerated chondrodystrophic short leg 

 with stocky, thick bone, extreme abduction at the wrist and 

 greatly enlarged, outspread feet, much more exaggerated 

 than its bassethound grandparent. This animal would appear 

 to possess a new quality of bone, different from that of either 

 parent stock and derived from its own peculiar combination 

 of ancestral factors, the result of which is this exaggerated 

 expression of achondroplasia. 



PLATE 13 



EXPLANATION OF FIGURES 



Second generation bassethound-Saluki hybrids showing various conditions of 

 leg length and bone type, as well as other physical characters. 



1 931^. 4 932 c?. 7 817 <?. 10 798$. 



2 929^. 5 933$. 8 792^. 11 797$. 



3 930 cj 1 . 6 791^. 9 816^. 12 795$. 

 Figures 1 to 5 are litter mates, as are figures 7 and 9, and figures 6, 8, 10, 



11 and 12. 



