ACTIVITY INDEX 
CONTROLS 
0.3ML 
SQUID EXTRACT 
J I I— J I I I L 
TEST 
TEST 
BLINDED 
' BLACKTIPS 
8-12-59 
j t—i i I i 
CONTROLS 
TEST 
TEST 
Fig. 7. Activity index during successive 2 -mm periods in two experiments, illustrating the difference in 
response of blinded blacktip sharks to human sweat and to food extract. 
