NATIONAL FISHERY CONGRESS. 



211 



This goes on until the obstacle is surmounted, if it Is not too great. Then, without 

 delay, the lamprey pushes on upstream, sometimes 8 or 10 kilometers, until clear water 

 and numerous ripples are found. Just above some ripple the lamprey begins to make 

 ready a secure place for a new generation. 



The male arrives first 

 and begins the nest build- 

 ing by removing and plac- 

 ing stones with his suctorial 

 mouth. In a few days he is 

 joined by a female, and to- 

 gether they labor away un- 

 til they have made a basin, 

 or in some cases a ditch 

 across the bed of the 

 stream. Now they fasten 

 themselves with their 

 mouths to stones at the up- 

 per edge of this basin, and 

 their bodies swing down- 

 stream and sway in the cur- 

 rent. 



Many hundreds of lam- 

 preys have been actually 

 counted on beds in the inlet 

 in a single season by ob- 

 servers at Cornell Univer- 

 sity, and in 1891 Professor 

 Gage saw there fully i,200. 

 In these nests the eggs, 

 after being fertilized, sink 

 to the bottom and adhere 

 firmly to the sand and 

 stones, being covered by 

 the lampreys stirring up 

 the sand with their tails. 

 After some days the eggs 

 are hatched and the young 

 lampreys, very much like 

 small angle- worms, burrow 

 into the sand. At first they 

 live in the sand at the bot- 

 tom of the nests, but soon 

 make their way to the sand along the banks of the stream. Here they remain for 

 perhaps two years or longer, with their eyes only rudimentary and their mouths 

 valvular, feeding on very minute organisms that live in the mud and sand. 



It is said that the adult lampreys die soon after spawning, but this is not fully 

 determined. It is also believed that some may return to the lake. When the young 



Mouth of luke lamprey (Petromyzon marinus unicolor). Reproduced from 

 drawing by Mrs. S. H. Gage. E, eye; S O, sense organs. 



