In the sea it is necessary to use sonic mechanisms for sightings 

 and recognition. If one goes into the sea one realizes that one's 

 range of vision even under the best of circumstances is rarely 

 beyond lOO feet and most of the time is less than that even near 

 the brilliantly lit surface of the tropical seas. With sonic means, 

 one's range is extended up to several miles under the best of 

 circumstances and under the worst to a few hundred feet. 



Recently we have obtained evidence that shows that the 

 dolphins communicate most of their information in the band of 

 frequencies extending from about 8 kilocycles to 20 kilocycles 

 by means of whistles and sonic clicks." However, as shown by 

 Schevill and Lawrence, they can hear sounds at least to 120 kilo- 

 cycles'' and as shown by Kellogg can produce sounds at least 

 to 170 kilocycles.'" We have recently been investigating the 

 higher frequency bands in these animals and have reliable 

 evidence that they can hear at least to 200 kilocycles and can 

 produce sounds to at least 200 kilocycles.' " With the proper 

 electronic equipment one can listen to the nearer portions of the 

 upper band and quickly determine that they can transmit in 

 these bands without the necessity of transmitting in the (lower 

 frequency) communication band. The high frequency informa- 

 tion is broadcast in a narrow beam off the front of the beak as 

 was first detected by Kenneth Norris.'* 



In these bands we find that they can produce musical tones 

 or individual clickings or hissing-like noises. Recently we have 

 found that an emotionally upset animal threatens other animals 

 and humans by productions of very large amounts of energy 

 both in the sonic communication band and in the ultrasonic 

 bands. Recently we have had the opportunity of working with 

 an old bull of 450 pounds weight who is so old his teeth have 

 been ground down flat. In terms of his skeleton, he is the most 

 massive animal we have ever seen. When he is irritated, his 

 "barks" have sizable amounts of energy from about 0.5 to at 

 least 300 kilocycles. He is also capable of transmitting in bands 



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