214 REPORT OF THE COMMISSIONERS OF 



have never been known to show any tendency or ability to climb, probably because there 

 are no rapids or mere low falls in the streams up which they would run. In fact, as 

 the inlet is the only stream entering into Cayuga Lake in this region which presents 

 suitable spawning conditions and no obstructions, it can be seen at once that all the 

 lampreys must spawn in this stream and its tributaries. 



In "running" they move almost entirely at night, and if they do not reach a suitable 

 spawning site by daylight they will cling to roots or stones during the day and 

 complete their journey the next night. This has been proven by the positive 

 observation of individuals. Of the specimens that run up early in the season, about 

 four fifths are males. Thus the males do not exactly precede the females, because we 

 have found the latter sex represented in the stream as early in the season as the 

 former, but in the earlier part of the season the number of males certainly greatly 

 predominates. This proportion of males gradually decreases, until in the middle of 

 the spawning season the sexes are about equally represented, and toward the latter 

 part of the season the females continue to come until they in turn show the greater 

 numbers. (See tables of weir catch, given later.) Thus it appears very evident that in 

 general the reproductive instinct impels the most of the males to seek the spawning 

 grounds before the most of the females do so. However, it should be said that neither 

 the males nor the females show all of the entirely sexually mature features when they 

 first run up streams at the beginning of the season, but later they are perfectly mature 

 and "ripe" in every regard when they first appear in the stream. When they migrate 

 they stop at the site that seems to suit their fancy, many stopping near the lake, others 

 pushing on four or five miles further up stream. We have noted, however, that later 

 in the season the lower courses become more crowded, showing that the late comers 

 do not appear to attempt to push up the stream as far as those that came earlier. 

 Also, it thus follows from what was just said about late running females, that in the 

 latter part of the season the lower spawning beds are especially crowded with females. 

 In fact, during the early part of the month of June we have found, not more than half 

 a mile above the lowest spawning bed, as many as five females on a spawning nest 

 with but one male; and in that immediate vicinity many nests indeed were found at 

 that time with two or three females and but one male. 



Having arrived at a riffle or shoal which seems to present suitable conditions for a 

 spawning nest, the individual (or pair) commences at once to move stones with its mouth 

 from the center to the margin of an area one or two feet in diameter. When many 

 stones are thus placed, especially at the upper edge, and they are cleaned quite free of 

 sediment and algae, both by being moved and by being fanned with the tail, and when 

 the proper condition of sand is found in the bottom of the basin thus formed, it is 

 ready to be used as a spawning bed or nest. A great many nests are commenced and 



