118 DEPARTMENT OF THE NAVAL SERVICE 



6 GEORGE V. A. 1916 



;and resting the other half on the bottom, thrust the head out of the water far enough 

 to expose the muzzle and eyes, and there they remained ogre-like, to an extraordinary 

 •degree, and motionless, as if watching intently the moving light. In a few minutes 

 they began to sink back slowly and almost imperceptibly, and withdrew into dark- 

 ness. Next night, this sigular behaviour was not observed except in one case. The 

 eels paused at the line of light, but after a half hour or so, began to shoot rapidly 

 past and remained in the upper part of the lighted area the rest of the night. Less 

 and less fear of the swinging lamp was manifested night after night, luitil they 

 seemed to pay little or no attention to it. 



It has been remarked that when first put in, the fish showed no sc-liooling ten- 

 dency, indeed seemed to manifest distrust of one another; but as time passed, they 

 became more social, and would often be seen during the day lying side by side under 

 the overhanging bank. When disturbed they scudded into the stream, stirred up a 

 cloud of mud at one point, when it settled only the head of the eel could be dis- 

 cerned. It was at length seen that the fish buried itself tail first. x\ll the time the 

 water was gradually falling and its temperature rising, and at length the eels ceased 

 to lie by day vmder the bank, but their heads were to be seen here and there, though 

 barely visible in the mud. Trial was made, and its temperature was found to be several 

 degrees cooler than that of the water — a good reason for the fish burying themselves 

 in it. 



It will be seen that these two experiments were conducted under some objection- 

 able conditions : — 



(1) The fish were penned, not free. 



(2) They had been taken from salt-water and put into fresh water or vice versa, 

 without in one case passing through slowly changing degrees of salinity. 



(3) The season for migration to fresh water had long passed. 



Waiving the modifying influences of these conditions and summing uji the results 

 •of the tests we see evidence that — 



(1) The fish were certainly afraid of the light at night. They would pause on the 

 line of illumination; move slowly until about half the body was exposed, and then 

 hurry past. As a rule, they soon returned to darkness, though after three or four 

 nights experience they would linger a long time in the light. 



(2) The longer they were in the pen, the less fear they showed. 



(3) The moving light was at first fairly effective, but after a night or two they 

 paid little attention to it. 



(4) That they failed to appear except at rare intervals in the illuminated end 

 of the pen after the third night was probably due to a growing consciousness of their 

 being impounded. 



All things considered it seeems very unlikely that their ascent could be arrested 

 by such means. 



