6 MIGRATION OF ADULT SOCKEYE SALMON. 
and other live stock. This button comes in two separate halves, each 
with a hollow central extension which forms the shaft of the com- 
plete button. The shaft of one half of the button is small enough 
to pass through the shaft and long enough to extend slightly beyond 
the face of the other half. When placed together in the proper 
position the two halves are fastened by means of a special crimping 
tool. This is built on the general pie of a pair of pliers; but the 
jaws meet only toward the tips, at which points are conical elevations. 
By fitting these elevations into the open ends of the shaft and closing 
the tool firmly, the end of the smaller inner shaft is spread sufficiently 
to prevent its being pulled back through the outer shaft. 
he buttons were made of either silver or aluminum. Some fear 
was entertained that the aluminum might corrode in the salt water 
sufficiently to make it difficult or impossible to read the numbers, 
but in this experiment there was absolutely no difficulty on this 
account. No corrosion is noticeable on any of the buttons returned, 
although some of them must have been three or four weeks in prac- 
tically pure salt water. This is contrary to the experience of Greene,* 
who found that salt water had astrongly corrosive action on aluminum 
buttons of similar style. This may have been due to some slight 
difference in the alloy of which the buttons were made. 
The buttons were attached to the upper lobe of the caudal (tail) 
fin. It was first necessary to cut a hole of the proper size to admit 
the shaft of the button. This was done by means of an ordinary 
leatherpunch. Figures 1 to 4, Plate I, show, in situ, both sides of two 
buttons which were returned. 
The operation of attaching the tags required, usually, less than 
one minute, and no particularly unfavorable results of tagging were 
noticed. At some of the stations where the marking was done the 
fish were held in crates until after the marking for the day was com- 
plete, and it was noticed that they soon recovered from the effects 
of being out of water while the tags were being attached and were 
a ken in perfect condition when liberated. ; 
eports that the tags were “worrying” the fish and causing them 
to wear their tails in an effort to remove the tags were investigated 
and found to be quite unfounded. Tails of several fish have been 
preserved and show no indication of such wearing as had been 
asserted. Figures 1 and 2, Plate I, are from such a specimen. 
The fish to be marked were taken from the traps at the time of 
lifting and were held either in crates or in one of the pockets of the 
spiller until they could be marked and released. 
MARKING STATIONS. 
Marking stations were established at five points in Puget Sound, 
as follows: Near Sooke, Vancouver Island, British Columbia; Salmon 
Banks, just south of San Juan Archipelago; near Point Partridge, 
Whidby Island; near Village Point, Lummi Island; and at the last 
trap in American waters on Point Roberts. For convenience these 
have been designated in the following pages as stations A, B, ©, D, 
and EH, respectively. 
oo SE a a eens 
a Greene, Charles W.: The migration of salmon in the Columbia River. Bulletin, U. S. Bureau of 
Fisheries for 1909, Vol. X XIX, pp. 129-148. Washington, 1911. 
