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THE AMERICAN NATURALIST [Vol. LIII 



a fresh hold. This was repeated several times, ])ut at last 

 the sucking-fish dropped off and swam away into deeper 

 water. 



A shark, which I hooked at Tortugas, had two Eche- 

 neises and one Kemora on it. Being rapidly dragged up 

 on the beach, the attendants did not let go until the shark 

 was high and dry. One Echeneis was captured but the 

 other two ' ' suckers ' ' got back in the water, and in many 

 other cases I have been unable to bring the fish out with 

 the shark. Dr. Townsend, however, writes (1915) that he. 

 has taken many sharks while on the United States Fish- 

 eries Steamer Albatross, and that nearly all of them came 

 aboard with one or more Echeneises attached. Thus it 

 would seem that in some cases the Echeneis holds fast and 

 that in others it lets go. The causes of these different 

 actions are not clear. 



However, it is after all not a question of whether the 

 sucking-fish lets go when brought into the air, but whether 

 it can stand the strain of hauling in a heavy turtle or large 

 fish. Hence the question is one to be settled by experi- 

 ment and if possible by mathematics. 



Holder (1905) has been quoted a- liaviii-- Iricd the ex- 

 periment but without results since iii> Hi.-kci'^'' would 

 not leave the sides of his boat to lay hold of tlie turtles 

 and sharks, record has been found of any similar ex- 

 IH'riments. In the same paper Holder speaks of lifting a 

 1 tucket of water by a Eemora which gripped the bottom 

 with its disk. 



Dr. C. H. Townsend, in an article in the Bulletin of the 

 Xew York Zoological Society (1915), describes experi- 

 ments to test the holding powers of sucking-fish in the 

 New York Aquarium. A two-foot specimen (size of disk 

 not noted) held by the tail lifted a pail half full of water- 

 total weight 21 pounds. A second, 26.5 inches long and 

 having a disk 5.5 inches in length, supported a pail and 

 water wciglnng 24.25 pounds. Had a deeper bucket been 

 UM'd ,^0 that the water w^ould not spill out, Dr. Townsend 

 thinks that the li.-h could have lifted an even greater 



