306 THE DUCTLESS GLANDS 



from the three cretins when about one year old was followed 

 by only slight symptoms. According to Simpson, age is an 

 important factor with regard to the effects of both thyroid- 

 ectomy and parathyroidectomy. The " typical cretins " of 

 Simpson are described as " small and stunted, with broad 

 faces and rickety limbs. The wool was coarse, but did not 

 tend to fall out." In some of the young animals (cats and dogs) 

 operated on by Vincent and Jolly interference with growth 

 was very striking, but the other " cretinoid " symptoms were 

 absent. 



Basinger in 1916 carried out an extensive research on 

 thyroidectomy in rabbits. Out of 140 animals operated upon 

 "typical cretinism" was produced in 86. The experiments 

 were carefully controlled as to feeding, and selection of subjects 

 and normals from the same litters. The thyroidectomy was 

 performed at the age of 2 to 3 weeks when the body weight 

 was about 175 gms. Great care was taken to remove all 

 thyroid tissue, leaving the external parathyroids intact, but it 

 was subsequently found that in a considerable proportion of 

 cases minute bits of the gland had been left behind and pre- 

 vented the onset of cretinism. In different litters the propor- 

 tion of successful results varied from 25 to 90 per cent. 



About two weeks after the operation the onset of cretinism 

 was detectable. The hair became dryer than normal, did not 

 lie smoothly and could easily be pulled out. Retardation of 

 growth was noticeable as early as the third week ; it was 

 greatest from the eighth to the twelfth weeks. By the end 

 of the tenth week the average weight of the cretins was 750 

 gms., while that of the controls was 1400 gms. The posture 

 of the cretins was typical. The bones were short and the 

 muscles of the limbs too weak to support the body weight. 

 The bones showed a pseudo -rickety condition (Hofmeister's 

 " chondrodystrophia thyreopriva "). The skin became in- 

 creasingly dry and scaly and finally eczematous. The typical 

 "pot belly " seen in human cretins developed. No evidence 

 of the typical myxcedema such as is seen in human cases was 

 observed. Neither did chronic, progressive cachexia appear 

 in any of the cretins, although they were kept for a year. 



Trail-fusion of normal blood serum into the cretins had no 

 apparent effect on their condition. Some improvement, how- 

 ever, resulted from transfusion of serum from thyroid-fed 



