194 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
become much emaciated and some of them succumb, notwithstanding 
clams and fish are fed to them. 
The tags were cut from sheet copper, as this metal is cheap and 
withstands the action of salt water for a long time. A few tags made 
of pure sheet tin were used, but they proved to be unsatisfactory. 
The copper tags were from five-sixteenths to three-fourths of an inch 
long, and one-fourth of an inch wide. A small hole was punched in 
one end, through which a fine copper wire was passed, attaching the 
tag to the fish. The average weight of the tags, with wire, was 0.65 
gram, or about one-fourth that of a 10-cent silver piece. 
The places of attachment were the bases of the three dorsal fins, the 
bases of the anal fins, and the upper and lower caudal lobes. Most of 
the tags were fastened to the upper part of the caudal fin, near its 
junction with the peduncle, where the rays are toughest and the tags 
are least liable to be torn out. ‘To facilitate the passage of the wire 
through the fin an aneurism needle was used. After the weight, 
length, and sex of the fish were determined and recorded, and the tag 
was attached, they were towed into the sound or bay in live-cars and 
turned loose. 
The record kept for each tagged fish comprised the following items: 
Tag number, position of the tag, date when released, where released, 
the weight, length, sex, and spawning condition (whether spent or 
immature). 
In order to acquaint fishermen and fish-dealers with the purposes of 
the tagging, and to encourage the preservation and return of the tags, 
a circular was printed and distributed in the fishing towns in Novem- 
ber, 1897. The circular contained a cut of a cod showing the position 
of the tags, and asked that any person coming into possession of a cod 
having such a tag forward the latter by mail to the U. S. Fish Com- 
mission, Washington, D. C., or to the U. S. Fish Commission station, 
Woods Hole, Massachusetts, together with the following information 
concerning the fish: The date when caught; on what grounds taken; 
weight before being dressed; total length measured from end of nose 
to end of tail; sex; and whether milt or eggs were ripe, large but not 
ripe, or immature. 
Additional publicity was given to the experiment by a number of 
timely articles in the newspapers of New York, Boston, and other 
large cities, as well as in the press of the fishing towns. The novelty 
of the scheme excited unusual interest and the hearty cooperation of 
the fishermen was secured, as shown by the large number of tags 
recovered and the filing of full data regarding the captured fish. 
The tagging began each winter about the Ist of December and con- 
tinued for 2 or 24 months. The work was usually brought to a close 
by the formation of anchor ice and the consequent killing of all the 
fish that remained in the cars. 
