GENETIC TYPE AND THE ENDOCRINES 95 



test we must now account for the exaggerated condition in 

 the F x bassethound-bulldog leg in some other way. 



The bulldog and bassethound parent stocks are illustrated 

 in figures 1 and 2 of plate 19, and three Fi hybrids from 

 this cross are shown in figures 3, 4 and 5 of the same plate. 

 The legs in all the hybrids are fully as short or shorter than 

 those of the pure bassethound parent (fig. 2). 



Four matings were made between two tested pure basset- 

 hound bitches and two prize stock highly typed bulldogs. 

 These matings whelped litters of eight, two, seven and six 

 puppies, a total of twenty-three Fj hybrids. All were quite 

 uniform in body size and form and in the characteristic con- 

 dition of the leg deformity, and were fairly vigorous animals 

 in spite of their distorted appearance. A large majority of 

 them lived to adult life, were mated, and produced 150 off- 

 spring. Many important modifications in the head and body 

 will be considered in other connections. 



Leg growth in the bassethound-bulldog F. hybrids. Twenty- 

 three fertile matings were made between F, hybrids, using 

 seven bitches as matrons and four males for stud. Among 

 these are both brother-sister matings and cross-line matings. 

 The twenty-three whelpings gave litters varying in size from 

 only a single pup up to ten in the litter. In all 150 individuals 

 were produced in the F 2 generation. This gives a large 

 statistical sample for analysis of the genetics of the leg 

 conditions. 



The F L , generation hybrids from this cross again showed, 

 as has been seen for the bassethound-slicpherd and basset- 

 hound-Saluki crosses, the typical Mendelian segregation ex- 

 pected for a single factor dominant character. Among the 

 150 individuals, approximately three out of every four had 

 short, bent legs and one out of four had long, straight legs. 

 The diagnoses for leg condition were made in some cases 

 on puppies which died when quite young, and although these 

 are probably correct, they cannot be as accurate as the meas- 

 urements and estimates made from the large number of adult 

 animals later available for study. The legs of the newborn 



