490 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



division there had been picked out 203,479 bad eggs, which would make 

 the original number 3,106,456. I am inclined to think the former esti- 

 mate is nearest to the truth; but as the latter has been used by all the 

 recipients of eggs in estimating their balances, I have used it in the 

 statement of hatching and distribution, to be given below. 



4. — MARKING SALMON FOR FUTURE IDENTIFICATION. 



At your suggestion, I undertook, iu 1872, to mark the salmon that 

 had been used as breeders and set free again in the river, so that some- 

 thing might be ascertained in relation to the length of their absence 

 from the river, their rate of growth, &c. 



The first mode adopted was the use of an aluminum tag about half 

 an inch long and a quarter of an inch wide, stamped with a number 

 wbicb corresponded with a record showing the sex, length, and weight 

 of the fish, and the date of liberation. This tag was at first attached 

 to a rubber band that slipped on over the tail of the fish. This mode 

 was quite defective, and led to no favorable results. Those bauds that 

 were loose probably slipped off, and those that were tight enough to stay 

 on cut through the skin of the fish, and produced a wound that probably 

 resulted in death. "When the impracticability of this mode became 

 manifest, it was abandoned, and the tag was attached to the rear margin 

 of the first dorsal fin, where it would least interfere with the motion of 

 the fish, and where the action of the latter in swimming would give it 

 the least lateral motion, and it would therefore be least likely to wear 

 out of its place. The attachment was by means of a piece of fine 

 platinum wire passed through a hole in the tag, and by means of a 

 needle through the edge of the fin, the ends being carefully twisted 

 together and trimmed with scissors. This mode was exclusively em- 

 ployed in 1873, and was partially successful. The tags, to be sure, did 

 not stay so long as was desired. Five or six months after the liberation 

 of the salmon in the river, a good many specimens were taken with the 

 tag still adherent, but of those that were taken a year and a half after- 

 ward not one was found with the tag on. Probably it was attacked by 

 some destructive acid in the water and so softened that the wire on 

 which it swung cut its way out and let it fall off. Some of the tags on 

 salmon turned into the fresh pond were found after a while to be in a 

 soft and brittle condition. The wire, however, remained in a good many 

 cases, and the kind of wire and mode of attachment served to identify 

 a number of salmon afterward caught as of the number marked and 

 liberated in 1873. 



The first marking was. as stated above, in 1872. In the spring of 

 1873, a reward was offered and thoroughly advertised among the fish- 

 ermen, for the return of any tagged salmon, with statements of the time 

 and place of capture. Not one was brought. In 1874, the offer was 

 repeated, and was so far successful that twenty of the salmon turned out 

 the preceding autumn were returned to me between the first of Janu- 



