■Oct. la, 1924 Postnatal Growth of the Single-Comb White Leghorn 
383 
Pancreas. —Figure 18 shows the 
increase in absolute and percentage 
weights of the pancreas plotted against 
gross body weight. The formulas are: 
plotted against age, except for an initial 
flattening of the first part of the curve. 
There seems to be a good deal of varia¬ 
tion in the distribution of the cases, 
Fig. IS.—Weight in grams of the pancreas, shown by the heavier line with the individual cases. The 
lighter lino represents the percentages of the net body weight 
Y = X 0 * 22 + 0.0007X - 2.23 
from 40-1,500 gm. gross body weight, 
F = 0.00042 (X-1,500) -f 3.82 
from 1,500-2,500 gm. grossbody weight. 
especially toward the upper end of the 
curve. This may be due in part, al¬ 
though not entirely, to the greater 
difficulty in removing the pancreas free 
from all fat, mesenteries, etc. 
In general, by way of summary, it 
may be said that the parts of the diges- 
Fig. 19.—Absolute and percentage weights of the trachea and lungs (combined), plotted on gross body 
weight 
Y represents the weight of the pan¬ 
creas in grams and X the gross body 
weight also in grams. 
This chart likewise resembles the 
other charts for the digestive system. 
Here also there is no marked difference 
in the curve when these weights are 
tive tract do not show any marked 
differences in their growth rates (figs. 
13 to 17). The curve for the weight of 
the liver seems to differ slightly, in¬ 
creasing a little more slowly and uni¬ 
formly throughout the entire range. 
