Harper, Behavior of Corethra. 



'445 



pupa lacks the special adaptations of the larva and is more like an 

 ordinary animal. Its reactions to light are more marked than 

 those of the larvae. 



a 



Fig. 2. 



Fig. 3. 



Fig. 2. Diagram showing directions taken in the first ten movements of a larva, produced while 

 the jar was being tapped on side a. 



Fig. 3. Diagram showing the directions assumed in the next thirty movements, made while tap- 

 ping was continued at a, showing effects of acclimatization. 



Experimejit i. — The latter show^ a distinct response which is most 

 marked in animals just brought into the laboratory and attuned 

 to the out-of-door intensity. These collect on the lighted side of 

 an aquarium. For experiments larvae were pl:iced in a trough 

 4x4x18 inches, with glass ends and blackened interior, and 



Fig. 4. Diagram of food reaction, showing movement in seizing an object applied as a stimulus 

 at posterior end in position i. 



lighted from one end, sometimes with sunlight and sometimes 

 with a 32 candle power incandescent lamp. In the most marked 

 responses noted the animals zigzagged to the lighted end in a few 



