222 REPORT OF THE COMMISSIONERS OF 



often moves the same stone several times, and may even attempt many times to move 

 a stone that has already been found too heavy for it; but sooner or later the rock may 

 become undermined so the water will aid them, and they have no way of knowing 

 what they can do under such circumstances until they try. If this were to be likened 

 to a quality of the human mind, it could as well be called perseverance as forget- 

 fulness. Also, the repeated moving of one stone may subserve the same purpose for 

 the lamprey in covering its eggs with sand as would the less frequent removal of many. 



When disturbed on the spawning nest, either of the pair will return t© the same 

 nest if its mate is to be found there; but if its mate is at another place, it will go to it, 

 and if its mate is removed or killed, it is likely to go to any part of the stream to 

 another nest. When disturbed, they often start up stream for a short distance, but 

 soon dart down stream with a velocity that is almost incredible. They can swim 

 faster than the true fishes, and after they get a start are generally pretty sure to make 

 good their escape, although we have seen them dart so wildly and frantically down 

 stream that they would shoot clear out on the bank, and become an easy victim of the 

 collector. This peculiar kind of circumstance is most likely to happen with those 

 lampreys that are becoming blinded from long exposure to the bright light over the 

 clear running water. If there is a solitary individual on a nest when disturbed, it may 

 not return to that nest, but to any that has been smarted, or it may stay in the deep 

 pool below the shallows until evening, and then move some distance up stream. 

 When the nest is large and occupied by several individuals, those that are disturbed 

 may return to any other such nest. We have never seen any evidence of one female 

 driving another female out of a spawning nest; and from the great number of nests in 

 which we have found the numbers of the females exceeding those of the males, we 

 would be led to infer that the former live together in greater harmony than do 

 the males. 



Under the subject of the number of eggs laid, we should have said that at one 

 shake a female spawns from twenty to forty. We once caught in fine gauze twenty- 

 eight eggs from a female at one spawning instant. In accordance with the frequency 

 of spawning stated, and the number of eggs contained in the body of one female, the 

 entire length of time given to the spawning process would be from two to four days. 

 This agrees with the observed facts, although the lampreys spend much time in 

 moving stones and thoroughly covering the nests with sand. Even after the work of 

 spawning and moving stones is entirely completed, they remain clinging to rocks in 

 various parts of the stream, until they are weakened by fungus and general debility, 

 when they gradually drift down stream. 



In forming nests, there is a distinct tendency to especially utilize those sites that 

 are concealed by overhanging bushes, branches, fallen tree tops, or grass or weeds, 



