484 



ALFRED O. GROSS 



In the converse of the above experiment, blue opposed to red, 

 the larva was oriented at c by the blue light. When at d the 

 red light was turned on but the blue being a much greater stimu- 

 lus than the red, the larva continued apparently on an unin- 

 terrupted course to / intersecting the arc of the circle at y. In 

 a similar way this course may be approximately recorded on the 



Fig. 21 A typical record of a larva in response to the red-blue pair 

 of lights. A and B are the paths followed by the larva started from the left 

 side and from the right side respectively. The arrows indicate the position of 

 the larva when the second light was turned on. The dots show the position of 

 the larva at ten-second intervals. The quadrants in A and B and figure 21 C 

 are used to illustrate the method of constructing the diagrams of the reaction 

 records of Calliphora larvae shown in figures 22 to 33 inclusive. 



diagram by y' as any number of additional such records may 

 be. A complete diagram of the reaction records of the larvae 

 to the balanced red and blue lights is shown in figure 22. Here 

 out of 14 trials all of the animals were driven by the blue into 

 the red as in the typical record, figure 21 A. The records of 

 a second series of experiments in which the colors were inter- 



