ZOOLOGICAL SOCIETY BULLETIN. 



347 



the Sportsnifii's Show in March, permission 

 for their transfer out of season having been 

 granted by State Fish Commissioner Whipple. 

 The vearHng black bass and }ello\v perch 

 raised artificially, and exhibited at the same 

 show, by Mr. H. W. Beeman, of the Wara- 

 maug Black Bass Hatchery, at New Preston, 

 Conn., were also presented to the Aquarium. 



Sczi'age Tests. — The Metropolitan Sewerage 

 Commission has been granted the temporary 

 use of one of the laboratories at the Aquarium 

 and is at work on the study of the water and 

 bottom deposits of the harbor. A launch has 

 been engaged and samples of water and mud 

 are being brought in for examination. Mud 

 samples from different levels are obtained by 

 boring, and all samples are tested chemically 

 and bacteriologically. 



Deposits of the heavier sewerage matter lie 

 on the bottom of the harbor in some places 

 many feet in thickness. The work is most 

 important and the results should demonstrate 

 the danger of emptying the sewage of Greater 

 New York and vicinity into the harbor. 



Sea- Turtle s. — The measurements and 

 weights of large sea turtles are so seldom 

 given with exact figures that the following, 

 relating to the largest specimens received at 

 the New York Aquarium, should be placed on 

 record : Green Turtle, ( Chelonia my das) , from 

 Key West, Florida. September, 1906. Ex- 

 treme length 5 feet q inches, lensrth of top 

 shell 4 feet 6 inches, length of under shell 3 

 feet 4 inches, width of top shell 3 feet 5 inches, 

 male, weight 540 pounds. Loggerhead Turtle, 

 (Tlialassochelys caretta), male, captured in 

 New York Bay, June 20, 1906. Extreme 

 length s feet 9 inches, length of top shell 3 

 feet 10 inches, length of under shell 2 feet 8 

 inches, width of top shell 2 feet 10 inches, 

 weight 395 pounds. 



Indian Visitors. — Mr. E. W. Deming, the 

 artist, with three of his Indian acquaintances 

 from the southwest, to wliom he had been 

 showing the sights of New York, visited the 

 Aquarium one day last summer. 



Indians are stoical, and usually do not say 

 much to white men about their impressions, 

 but at the Aquarium they began to unbend. 

 The big sea-turtles and the brilliantly colored 

 tropical fishes were animals of a character so 

 unexpected, that their interest at last found 

 expression, and they came nearer an animated 

 discussion than at any time during their trip. 

 Mr. Deming afterward reported that the Aqua- 

 rium, and the Winchester Arms Co.'s exhibit 

 were the attractions which made the deepest 

 impression on the Indians. 



THE USES OF THE FINS OF FISHES. 



By R.-WMOND C. OSBURN. 



THE fins are the most obvious organs of 

 the fish, and although a great deal has been 

 written about their structure, the knowl- 

 edge of their functions seems to have been 

 largely left unwritten, probably because it seems 

 so evident that their uses are those of propelling, 

 balancing, and steering the body in locomotion. 

 While in a general way this is true enough, 

 it is our purpose here to inquire how the vari- 

 ous fins are applied to the performance, of 

 these functions. The writer has recently con- 

 firmed some observations made a number of 

 years ago, by experimental work and many 

 careful observations on the uses of fins of the 

 fishes at the New York Aquarium, and this 

 communication is written with the hope that 

 it will call the attention of visitors at the Aqua- 

 rium to the various uses of the fins, and to the 

 varied and complex movements which fishes 

 are able to perform. The general results of 

 this work may be briefly stated as follows : 



A. The pectoral fins have four distinct 

 uses : 



1 . They are used for steering and steadying 

 and for changing the course in swimming. 

 They are usually held against the side of the 

 body when the fish is swimming straight 

 ahead rapidly. 



2. When the fish remains suspended quietly 

 in the water these fins are the principal ones 

 used in keeping the equilibrium, and they are 

 then constantly in motion. 



3. When the fish is moving and wishes to 

 stop, the pectoral fins are thrown out at right 

 angles to the body, thus very greatly increas- 

 ing the resistance to the water and acting as a 

 brake. 



4. These fins are in most fishes capable of 

 being used to propel the body. Most fishes 

 can swim either forward or backward by the 

 movements of these fins and occasional forms 

 can move quite rapidly. For this use of the 

 fins the doctor-fish, (Teuthis hcpatus) and the 

 tautog, (Tautoga onitis) in the Aquarium are 

 worthy of study. 



B. The ventral or pelvic fins are less impor- 

 tant than the pectorals and are largely used to 

 supplement them. In many short-bodied fishes 

 they are situated directly or nearly beneath 

 the pectorals, and are used in conjunction with 

 them. They may be said to have the same 

 functions as the pectoral fins, although to a 

 less degree, and they may be seen to work in 

 harmony with, although not always to move 

 svnchronouslv with them. 



