40 IOWA STUDIES IN NATURAL HISTORY 
average minimum of 2.9 grams, or a total reduction of 57.3 per 
cent. This curve corresponds very closely to Schaper’s (‘02) 
curve which illustrates the changes in the total weight of Rana 
fusca during the corresponding period. Curve AE, fig. 2, 
illustrates the changes in the total length of the stomach and 
intestine during the same period. This curve also shows a rapid 
rise until the digestive tube has attained its maximum length; 
then an abrupt decline. It indicates a reduction from an aver- 
age maximum of 51 to an average minimum of 6 em., or a total 
reduction of 88.2 per cent. 
Curve AF, fig. 2, illustrates the changes in the length of the 
stomach alone. This curve drops abruptly until its low point 
is reached only a little later than the high point in curve AE. 
It indicates a reduction from an average maximum of 11 mm. 
to an average minimum of 5 mm., or a total reduction of 54.5 
per cent, which occurs somewhat earlier than the reduction in 
the length of the intestine and is followed immediately by rap- 
id growth both in length and capacity. Curve AC, fig. 1, il- 
lustrates the changes in the total weight of the stomach and 
intestine with contents. This curve is based on the average 
weight determinations multiplied by 5. It shows a rapid rise 
until the digestive tube has attained its maximum length; then 
an abrupt decline. It indicates a reduction in weight from 
an average maximum of 1.4 to an average minimum of .1 gram, 
or a total reduction of 92.8 per cent. Curve AD, fig. 1, il- 
lustrates the corresponding changes in the weight of the liver. 
It also is based on the average weight determinations multiplied 
by 5. This eurve indicates a reduction in the weight of the 
liver from an average maximum of 0.3 to an average minimum 
of .06 gram, or a total reduction of 80 per cent. The pancreas 
also undergoes material reduction in weight which is initiated 
somewhat earlier than the reduction in the length of the diges- 
tive tube and the weight of the liver. It also undergoes changes 
in form and in its position with respect to the liver and the du- 
odenum. By reason of the small size of the pancreas no at- 
tempt was made to illustrate its changes by means of curves. 
The curves representing respectively the length of the stomach 
and intestine and the total weight of these organs with contents 
