134 



THE UNIVERSITY SCIENCE BULLETIN. 



Relation Between the Weight of Pigs and the Percentage 

 Thymus by Weight, Using Litter Averages Throughout. 



Table No. 3 and curve No. 2 show practically the same tendency 

 as to table No. 2 and curve No. 1, i. e., as heavier and heavier pigs 

 are examined, the percentage of thymus by weight increases steadily. 

 There is practically the same inexplicable deviation or drop near 

 the center of the curve, and the possible maximum point centering 

 about pigs of a weight of 770 grams. 



table No. 3. 



Relation Between the Length of Pigs and the Percentage by 

 Weight of the Thymus, Using Length Group Averages 

 Throughout, Disregarding Litters. 



Table No. 4 and curve No. 3 show that as larger and larger foeti 

 (as regards length) are examined and classified regardless of litter, 

 there is a steady increase in the percentage thymus by weight. The 

 increase is not as uniform, however, as when the pigs are classified 

 according to litter, as will be shown by a comparison of curve No. 1 

 with curve No. 3. The former is the smoother. Hence from these 

 calculations on lengths, we may conclude that pigs tend to have the 

 same size thymus, relatively, as that of other pigs of the same litter, 

 regardless of individual pig lengths. 



