I'HE PARS BtrCCALIS OP THE HYPOPHYSIS 41 



3. GROWTH DISTURBANCES 



Little doubt can be entertained but that the pituitary gland 

 plays a significant role in the regulation of growth. Observa- 

 tions on clinical material which have been elucidated and ex- 

 tended by experimental operative work, more particularly by 

 that of Paulesco and Gushing, have shown rather clearly that a 

 hypersecretion of this gland results in an overgrowth of the 

 skeletal system (giantism and acromegaly), the opposite picture 

 of a pituitary deficiency being seen in dystrophea adiposo- 

 genitalis. 



Clear as such findings appear to be, it seems the more enig- 

 matical that the administration of this gland has failed to elicit 

 a definite growth accelerative response, indeed the response 

 most uniformly evoked being one of retardation. The evidence 

 so far presented is in many cases at least of such an equivocal 

 and uncertain natm-e as to come well within the limits of experi- 

 mental error and to even be subjected to an opposite interpre- 

 tation. This can be said not only of the feeding experiments 

 of different investigators, but of single investigators as well, 

 and only to the latter do we need to address our attention for 

 a moment. Aldrich ('12), from the administration of anterior 

 lobe to pups, concluded that growth was not stimulated nor 

 retarded, but later concluded from work on white rats that growth 

 retardation occurred (Aldrich, '12). Robertson, in the most 

 elaborate work which has yet appeared upon this subject and 

 who has not only used large numbers of animals of the same 

 species (white mice), but who has also applied the valuable 

 adjuvant of refined statistical methods to his data, at first 

 concluded (Robertson, '16), "The administration of 0.125 gms. 

 per day per animal of fresh anterior lobe pituitary tissue to 

 mice, beginning at 4 weeks after birth (conclusion of the 

 second growth cycle), leads to retardation of growth during the 

 earlier portion of the third growth cycle, between the 6 th and 

 20th weeks. In the latter part of the third growth cycle, how- 

 ever, from the 20th to the 60th weeks after birth, the growth 

 of the pituitary-fed animals is markedly accelerated, so that they 



