162 
JOSEPH HALL BODINE 
occur, but generally it has been found that the rate of output 
is approximately doubled three hours after feeding. The effects 
of a single feeding, however, last but a short time, depending 
upon the amount of food eaten. No detailed study of the effects 
of different amounts of different foods has been made, but an 
animal starved for forty-eight or more hours and then fed al^^■ays 
shows an increased output. This increase gradually rises as 
the weight increases until the animal gains its normal weight 
relations. Such results, showing that starved grasshoppers 
respond to ingestion of food by increased production of COo, 
agree with those for other forms, and especially with those of 
Allen {20) for Planaria. 
COj D.gm. p.hr. 
^^^^^~~-~l^ 
^ 
_^ 
r" 
^^^ 
/ 
t 
T, 
•ne-HRS. 
1 
1 
l,„ 
1 
1 
l|4a 
' 168 
Fig. 6 Curves show decrease in CO2 output by Melanoplus differentialis dur- 
ing starvation and increase after feeding. Abscissas represent time in hours 
indicated by numbers. Ordinates represent rate of CO2 output in grams CO2 
per gram total body weight per hour. Time at which feeding was begun indicated 
by arrow. See text for further description. 
CONCLUSION 
The results of the present study, as presented above, seem to 
indicate the extent to which comparisons between some of the 
physiological phenomena of insects and mammals can be made. 
It is found that the percentage of water an animal contains is 
characteristic for the particular species, and that it decreases 
with age and increasing body weight. When exposed to low 
temperatures, the animals respond by a decrease in water content 
and are thus prevented from freezing and possible destruction. 
