102 



GENERAL BIOLOGY 



point. In general, however, growth is accelerated 

 both in plants and animals by a slight increase of the 



MEAN TEMPERATURB 

 56FAHR. 53FAHR. 



ft: 



FIG. 36. Chart showing the correlation between the stage of de- 

 velopment of the frog on successive days and the temperature at which 

 it has developed. (From Davenport, after Higgenbottam.) 



normal temperature. This is well illustrated by the 

 accompanying chart (fig. 36). 



Effect of Chemical Agents. Since growth can 

 take place only at the expense of food substances 



