522 CHARLES R. STOCKARD AND E. M. VICARI 



was moderate internal hydrocephalus which is frequent in 

 those brains of the shape associated with the bulldog typed 

 head. 



The modified nature of the thyroid gland in this bitch, 

 9029, is illustrated in plate 94 (fig. 4). Her pituitary gland 

 presented an abnormal predominance of acidophilic cells, 

 having a distorted ratio of about 100 acidophiles to one 

 basophile. 



If we compare the conditions just discussed in these basset- 

 hound-bulldog parathyroids with those previously considered 

 for the dwarf Boston terrier-dachshund hybrids (plates 91 

 and 92), surprisingly few histologic differences can be found. 

 Probably the most definite difference between these two groups 

 is the much less frequent presence of sinusoidal capillaries 

 and spaces in the Boston terrier-dachshund parathyroids. 

 The principal cells and their patterns of arrangement, as 

 well as the occurrence and position of the bluish staining 

 cells, are much the same in both breed crosses, and the 

 cystic conditions and symptoms of arrested development are 

 confined to neither group. The failure to discover more 

 pronounced and consistent modifications in parathyroid his- 

 tology among these highly distorted and widely different 

 breed types merely indicates the difficulty of establishing a 

 definite histopathology in a simple and rather homogeneous 

 endocrinic gland as contrasted with the striking differences 

 in microscopic patterns presented by the thyroid and pituitary 

 glands. 



We have finally to proceed with the consideration of the 

 histologic nature of the endocrine glands in the cross between 

 the giant great Dane and the acromegalic typed giant St. 

 Bernard in order to secure a final broad comparison among 

 the giant, the normal sized and the dwarfed breed types. 

 The necessarily opposite growth deviations from the normal 

 in the production of giant and dwarf reactions should be 

 readily associated with widely contrasted patterns of pituitary, 

 thyroid and parathyroid glands if the secretions from these 

 glands are to be considered the mechanisms through which 

 the degree and type of growth are determined. 



