Otto Loewi performed an experiment in which he first electrically stimulated the vagus nerve connected to a frog heart. He then passed the fluid bathing this heart to a second chamber containing a second frog heart not connected to a nerve. What did Loewi observe?
A. The first heart showed a decrease in beat rate, but there was no change in the second heart.
B. The first heart showed an increase in beat rate, but there was no change in the second heart.
C. The first heart showed a decrease in beat rate and so did the second heart.
D. There was no effect on the beating of either heart.
E. The first heart showed an increase in beat rate and so did the second heart.
Answer: C
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