500 CHARLES R. STOCKARD AND E. M. VICARI 



behind all thyroid influences, but investigators studying- more 

 than one endocrine gland find it difficult to attribute the many 

 variations in thyroid quality and function to the stimulating- 

 influences of this pituitary substance alone. It must be re- 

 membered that in some dogs the thyroid gland functions 

 fairly well for some time after the pituitary has been com- 

 pletely destroyed. 



Certain further evidence to aid in the solution of these 

 problems may be derived from an examination of the pituitary 

 glands in the bassethound-bulldog hybrids, and we shall now 

 proceed to a discussion of this phase of our experiments. 



The Histologic Quality of the Pituitary Glands ix the 



Bassethound-Bulldog Hybrids axd the Possible 



Relations to Morphologic Distortions and 



Modifications in the Histologic Quality 



of the Thyroid 



We may repeat the idea presented previously that the co- 

 ordination of developmental processes among the different 

 organs and parts of the newly forming individual is deli- 

 cately and perfectly adjusted to bring about an harmoniously 

 proportioned body complex. Any slight change in the environ- 

 ment during the development of a given organ, such as a 

 momentary failure of the oxygen supply or circulation, 

 would allow other body parts to gain material advantage 

 over it, the seriousness of which would largely depend upon 

 the developmental stage of the organ at the time the handi- 

 cap occurred. These statements are fully substantiated by 

 numerous studies in the field of experimental embryology. 

 The pituitary gland, in its endocrinic predomination, is inter- 

 related with so many other organs that should it be involved 

 in developmental arrests or early handicaps, a number of 

 parts would suffer consequent developmental disturbances, 

 the symptoms of which would be structural distortions and 

 modifications in type. 



