GENETIC TYPE AND THE ENDOCRINES 419 



pars infundibularis and pars intermedia are larger in the 

 male. Since the body weight of women is less than that of 

 men, the proportional size of the female pituitary exceeds the 

 male even further than does its actual size. 



Rasmussen is of the opinion that there is a distinct positive 

 correlation between body length or height and the weight 

 of the pituitary, and that this correlation is closer than the 

 correlation between body weight and pituitary weight. In 

 both human sexes, a person of large stature will be found to 

 have a large pituitary. This is also true for the dog. 



The large dog breeds have large pituitaries, and the small 

 toy dogs have small pituitaries. However, the weight of 

 pituitary in milligrams per kilogram of body weight is higher 

 in the small dogs than in the larger breeds. This is clearly 

 seen by comparing text-figures 82, 83 and 84. As shown in 

 text-figure 82, hybrids from the dachshund and Boston terrier 

 cross, each weighing about 10 kilograms, have pituitaries 

 ranging in actual weight from less than 100 milligrams up 

 to about 300. The bassethound-English bulldog hybrids rep- 

 resented in text-figure 83, each of which weighed more than 

 20 kilograms, have pitutaries ranging in weight from about 

 180 milligrams to well over 400 milligrams. The giant speci- 

 mens represented in text-figure 84 range in body weight 

 from about 40 to 100 kilograms, and the actual weights of 

 their pituitaries vary from over 250 to over 600 milligrams. 

 Therefore, in general it is true for dogs that the larger the 

 stature the greater the weight of the pituitary, but also that 

 the smaller the stature the greater the relative weight of 

 pituitary per kilogram of body substance. 



The pituitary in the dog is not nearly so variable in size 

 as is the thyroid, nor do the size variations of these two 

 organs seem to be directly related. The variability of pitui- 

 tary weight in the dog is about comparable to the general 

 ratio of variability for the heart, kidney and liver, which 

 accords in general with the findings of Brown ('29) for 

 normal rabbits. 



