288 



WALTER S. HUNTER 



time does not really begin before the eleventh trial and decrease 

 in errors not before the seventh trial. In figures 6 and 7 the 

 curves again reveal the same characteristic. In the time 

 curve for pigeons nos. 5 and 8 (fig. 6) there is no permanent 



CO *o f^ ^^ '^^ CO *J^ f^ cr- 



»^ I I I ^ '^ -^ ^^ •7^ ff-J 



Ci oj ^ --0 to o 



»-- -~. »^ -^ -~ cv 



-^ «v Tria.ls 



Figure 6 — Time graphs for the first twenty-one trials of pigeons nos. 1, 2, and 7 

 (A) and nos. 5 and 8 (B) in labyrinth B. 



descent before the sixteenth trial. The error curve (fig. 7) 

 drops permanently after the sixth trial. The time curve (fig. 

 6) for pigeons nos. i, 2 and 7 falls after the tenth trial; and the 

 error curve (fig. 7), after the sixth. These are quite unusual 



I 



