96 CHARLES R. STOCKARD 



and 1 week old puppy in all breeds are rather short but in 

 almost every case can be distinguished from the short leg of 

 achondroplasia by the slender form and narrow, smaller foot, 

 as well as by the differences in length among the short legs 

 of litter mates. With this bassethound-bulldog cross the error 

 in leg classification is very small, if any, and would not 

 warrant the amount of work necessary for an histologic 

 examination in order to verify the classification. 



The achondroplasic F 2 animals in this cross again fall into 

 two groups : those very pronounced and probably homozygous 

 for the condition, and those with a less severe expression. 

 Yet in these hybrids the separation of the short legs into 

 the two groups cannot be done with such clearness as is 

 possible with both the bassethound-shepherd and the basset- 

 hound-Saluki crosses. On the other hand, the long legged F 2 

 animals in this cross are more clearly separated into two 

 classes of leg length than was possible in either of the former 

 crosses. Some of the long legged F 2 animals have straight 

 legs of about the same length as those in the foxhound, while 

 others have a much stockier and shorter leg, similar to that 

 of the bulldog. 



These differences in length of long legs and in thickness 

 of bones are due to differences in bone type. The leg bones 

 of the bulldog are thicker and shorter than the bones of the 

 foxhound, of which the bassethound is considered the achon- 

 droplasic leg mutant. On crossing the bulldog and the basset- 

 hound, the bone type or bone constitution of the bulldog is 



PLATE 19 



EXPLANATION OF FIGURES 



Cross between the bassethound and English bulldog showing inheritance of leg 

 length and other physical characters. 



1 English bulldog 903 J. 



2 Bassethound 216 $. 

 3-5 F, litter mates. 



3 694 <?, 695 J. 4 694 <?. 5 740 < 694 <?. 

 6-9 F 2 litter mates. 



6 917 <?. 7 916 c?. 8 918$. 9 919$. 



