^02 The Cyclostomes, or Lampreys 



as viewed from the standpoint of man, it does not need to be so 

 in order to perfectly fulfill all the purposes of the lampreys. 

 As shown abo^'e in the remarks on the spawning habits of the 

 brook lampreys, the important end which they thus accomplish 

 is the loosening and shifting of the sand to cover their eggs; 

 and the more the stones are moved, even in the apparently 

 indiscriminate manner shown, the better is this purpose achieved. 

 Yet, in general, they ultimately accomplish the feat of moving 

 to the lower side of the nest all the stones they have placed 

 or left at the upper margin. At the close of the spawning 

 season when the nest is seen with no large pebbles at is upper 

 margin, but quite a pile of stones below, it can be known that 

 the former occupants completed their spawning process there; 

 but if many small stones are left at the upper edge and at the 

 sides, and a large pile is not formed at the lower edge, it can 

 be known that the nest was forsaken or the lampreys removed 

 before the spawning process was completed. The stones they 

 move are often twice as heavy as themselves, and are some- 

 times even three or four times as heavy. Since they are not 

 attempting to build a stone wall of heavy material, there is no 

 occasion for their joining forces to remove stones of extraor- 

 dinary size, and they rarely do so, although once during the 

 past spring (1900) we saw two lake lampreys carrying the 

 same large stone down-stream across their nest. Although 

 this place was occupied by scores of brook lampreys, there 

 were but three pairs of lake lampreys seen here. It is true 

 that one of these creatures often moves the same stone several 

 times, and many even attempt may times to move a stone 

 that has already been found too heavy for it; but sooner or 

 later the rock may become undermined so that the water will 

 aid them, and they have no way of knowing what they can 

 do imder such circtmistances until they try. Also, the re- 

 peated 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 to the same nest if its mate is to be found there' 

 but if its mate is in 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 



