514 charles r. stockard and e. m. vicari 



The Quality of Parathyroid Glands in the Bassethound- 



Bulldog Cross and the Possible Relations to 



Modifications in Skeletal Growth 



The parathyroid glands in the bassethound and bulldog 

 and in their hybrid progeny are very probably related in 

 most important ways to the strange modifications in the shape 

 and quality of the bony skeleton and the overgrowth of the 

 skin. In spite of this probable relationship, it is extremely 

 difficult to locate either histologic or cytologic modifications 

 in the parathyroid epithelium which can be consistently as- 

 sociated with a definite skeletal distortion. The histologic 

 nature of the parathyroid is very simple and homogeneous 

 and, as mentioned before, the histopathology of so direct a 

 disturbance as parathyroid tetany has not been clearly estab- 

 lished, although the condition without doubt results from 

 deficiency in the amount of parathyroid hormone. Other diffi- 

 culties present themselves in any attempt to relate specific 

 histologic defects of the parathyroid with definite modifica- 

 tions in growth. One of the most evident of these difficulties 

 is due to the variable numbers of very small parathyroid 

 bodies present in the animal, all of which may not present 

 identical histologic conditions. It would be a most arduous 

 task to examine microscopically every parathyroid body from 

 each animal studied, even though one assumed that no small 

 particle had been overlooked. 



Yet in spite of these difficulties, it is essential in the present 

 study to investigate as far as practical the nature of the 

 parathyroids in the breed crosses showing such evident dis- 

 tortions in just those tissues with very high calcium require- 

 ments, such as the skeleton and skin. We recognize, of course, 

 the close interrelation of parathyroid and pituitary functional 

 activity, and from this it might be inferred that the definite 

 modifications in the pituitary histologic patterns which ac- 

 company certain structural distortions in these hybrids may 

 also be related to developmental arrests and histologic dis- 

 turbances in the parathyroid bodies. 



