494 The Cyclostomes, or Lampreys 



second, and it is on account of their greater abundance that 

 the lampreys' attacks on them are more observed. 



" There is no doubt that the bullhead, or horned pout (Ameiu- 

 rus nebulosus), is by far the greatest sufferer from lamprey 

 attacks in Cayuga Lake. This may be due in part to the slug- 

 gish habits of the fish, which render it an easy victim, but it 

 is more likely due to the fact that this fish has no scales and 

 the lamprey has nothing to do but to pierce the thick skin and 

 find its feast of blood ready for it. There is no doubt of the 

 excellency of the bullhead as a food-fish and of its increasing 

 favor with mankind. It is at present the most important 

 food- and market-fish of the State (New York), being caught 

 by bushels in the early part of June when preparing to spawn. 

 As we have observed at times more than ninety per cent, of 

 the catch attacked by lampreys, it can readily be seen how 

 very serious are the attacks of this terrible parasite which is 

 surely devastating our lakes and streams. 



Migration or "Running" of Lampreys. "After thus feeding 

 to an unusual extent, their reproductive elements (gonads) be- 

 come mature and their alimentary canals commence to atrophy. 

 This duct finally becomes so occluded that from formerly being 

 large enough to admit a lead-pencil of average size when forced 

 through it, later not even liquids can pass through, and it 

 becomes nearly a thread closely surrounded by the crowding 

 reproductive organs. When these changes commence to ensue, 

 the lampreys turn their heads against the current and set out 

 on their long journeys to the sites that are favorable for spawn- 

 ing, which here may be from two to eight miles from the lake. 

 In this migration they are true to their instincts and habits 

 of laziness in being carried about, as they make use of any avail- 

 able object, such as a fi:h, boat, etc., that is going in their direc- 

 tion, fastening to it with their suctorial mouths and being 

 borne along at their ease. During this season it is not infre- 

 quent that as the Cornell crews come in from practice and lift 

 their shells from the water, they find lampreys clinging to the 

 bottoms of the boats, sometimes as many as fifty at one time. 

 They are likely to crowd up all streams flowing into the lake, 

 inspecting the bed of the stream as they go. They do not 

 stop until they reach favorable spawning sites, and if they 



