60 



E. R. BENSLEY 



TABLE 1 



rapidly in weight during the first twenty days, reaching a weight 

 of 4490 grams, an increase of 1840 grams. Then it began to lose 

 weight and ten daj^s later was reduced to 3960 grams. At this 

 time the right lobe of the thyroid gland weighing 0.247 g. 

 was removed, and the animal was placed on a diet which in 

 series four had been found to keep the thyroid normal. The 

 animal was killed twenty-two days later. The left thyroid 

 weighed 0.214 g. but histologically showed no reversion to 

 colloid type, or indeed any change. 



Number twenty-four kept for twelve weeks on the mixed diet 

 showed no gain in weight at any point, the weight fluctuating 

 around the initial weight. 



The animals of this series show an interesting gradation in 

 thyroid activity correlated with the change in weight, as tested 

 by the amount of intracellular secretion antecedent present in 

 each case. In number three, in which the grade of hyperplasia 

 was highest, and the percentage gain in weight greatest, the thy- 

 roid cells contained little secretion antecedent. Number four 

 contained more secretion antecedent in the form of small vacu- 

 oles of stainable substance in the base of the cell. Number five 

 contained a great deal of secretion antecedent in the form of 

 small vacuoles of stainable substance in the outer pole of the 

 cell, and the majority of the cells of number twenty-four con- 

 tained still larger quantities of these substances, located in the 

 bases of the cells. 



These variations in secretory content have been tested by a 

 new method of staining sections, fixed in formalin zenker, with 

 phosphotungstic acid brasilin and wasserblau, which differen- 



