SALMOK AND TROTTT IN ALASKA. 67 



mann Platchery, where they were marked, only 2 of these fish were 

 obtained in 1906.'^ There is no doubt that these fish noted at the 

 hatcheries were identical with the fry so marked. In careful measure- 

 ments of over 7,000 sockeyes during two summers and casual inspec- 

 tion of many thousands during five seasons in Alaska, the writer has 

 seen but one example of a salmon without ventrals, and in that case 

 the fish was entirely without any indication that fins had ever begun 

 to develop and was doubtless a monstrosity. The 2 samples sent in 

 from Loring sliow the stubs of the fins just as would be expected from 

 an amputation performed in the manner stated. This experiment, 

 so far, supports the four-year theory. 



In the spring of 1904 several thousand of the yearlings trapped at 

 the head of Naha Bay were marked by the complete amputation of 

 both dorsals. These fish were the same age as the fry mentioned 

 above as marked the previous summer. There has been no record of 

 the return of any of these latter. It is believed that the handling 

 resulted in great loss and the percentage of survivors was too small to 

 obtain notice even if, as is probable, the complete regeneration of the 

 fin did not make the marking useless. A similar experiment at the 

 Clackamas hatchery in the summer of 1904 has so far produced no 

 result. 



Mr. Rutter made several experiments in branding fingerlings, and 

 reached the conclusion that it can be successfully done. Unfamil- 

 iarity with methods ordinarily used in branding led him first to try a 

 five-pointed star. As was to be expected, when the fish survived the 

 severe burn of the iron, which was seldom, the scar rapidly became 

 formless by obliteration of the points. Subsequent experiments de- 

 veloped that a wire is a better instrument, the heat being applied 

 wholly on fine lines, burning the skin but not injuring adjoining 

 tissue. Any design with lines which do not cross, and which will not 

 resemble in sharp angles or parallels the wounds of the teeth of preda- 

 tory arfimals, will answer. 



It is believed that if fin amputation is demonstrated as a feasible 

 mark it should be performed on the small fingerlings. Fish under 2 

 inches are less susceptible to injury by handling. The fingerlings, 

 after the formation of scales, are very easily injured, the scales part- 

 ing from the skin upon the least touch. Their struggles when handled 

 will almost infallibly produce abrasions. The experiment of anaestheti- 

 zing has not been made. 



Regeneration of lost parts. — Regarding reproduction of lost parts, 

 authorities differ. It was believed by Giinther '' that "the power of 

 reproduction of lost parts in Teleosteous fishes is limited to the deli- 

 cate terminations of the fin rays," etc. 



«■ Seven more of these marked fish have been reported taken at the Fortmann 

 Hatchery during the fall of 1907 up to September 29. 

 b Giinther, Introduction to the study of fishes, p. 188. 



