286 CHARLES R. STOCKARD AND A. L. JOHNSON 



Figure 2 is from a hybrid Dane by St. Bernard, both of 

 which breeds are long skulled. The foramen magnum in the 

 puppy is in the same relative position as in the adult. The 

 basioccipital bone is very long. The posterior segment of 

 the basisphenoid, which contains the sella turcica on its dorsal 

 surface, shows a large opening which represents an arrest 

 in the closure of the foramen, Rathke's pouch, through which 

 the hypophysis grows from the stomodaeum up into the 

 cranium. The black transverse line a short distance in front 

 of this foramen shows the position of the anterior epiphyseal 

 growth cartilage of the basicranium. This skull is quite nor- 

 mal in general respects and has the facial skeletal proportions 

 typical of the rather flat faced newborn puppy. 



The highly modified skull of a newborn bulldog typed puppy 

 is illustrated in figure 1. In addition to the usual bulldog 

 characteristics, this skull shows a cleft palate, which is a 

 rather common anomaly among such typed skulls. This defect 

 in the present case serves our purpose to advantage by per- 

 mitting a full view of the basicranium throughout its extent. 

 Through a rounding of the plate of the occipital bone in this 

 specimen, the foramen magnum is placed somewhat more 

 forward than it is in the long skull. The basioccipital is 

 short, but not disproportionately so. Through the cleft in 

 the palate it is seen that the two segments of the basisphenoid 

 are widely separated and that both are abnormally short. 

 At this age, the basicranial cartilages are present, but are 

 known to be dystrophic and deficient in their growth re- 

 actions. 



Three other skulls from older puppies are illustrated in 

 figures 4, 5, and 6. One of these (fig. 4) is a fairly typical 

 long skull, one is partially bulldog in type (fig. 5), and the 

 third (lig. (>) is a fully expressed bulldog type. 



The two long skulls have the foramen magnum in the usual 

 posterior position with the plane of the opening facing ventro- 

 posteriorly. In the bulldog typed skull (fig. 6), the foramen 

 magnum is more anterior in position and the plane of the 



