214 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Lampreys must be destroyed before spawning if they are to be exterminated. Nothing would be 
easier than to do this. A dam with a fishway — the fishway leading into an isolated inclosure — where 
the lampreys could be easily removed and disposed of, or a weir of some kind, could be constructed at 
slight expense. If this could be continued for three or four years in all the lakes and in the Oswego 
Eiver, the race could be extinguished and the lakes wholly freed from their devastations. 
In the diagram A represents perpendicular posts set in the stream and fastened, for the purpose 
of catching floating material that might otherwise tear or injure the weir below. B represents net 
wings for the capture of creatures running down the stream. 
C represents the main or chief net placed entirely across the stream 
to prevent passage either way. At D is the pocket or pen in 
which the fish coming up the stream will ultimately be found, 
being guided by the various wings of netting or wire E and F. 
It can be seen that if a weir for this purpose were 
established in the inlet of Cayuga Lake, not only would 
but what is much more, it would give some vastly im- 
portant absolute facts to the State authorities upon 
culations for more extensive operations at other lakes 
for another year. Also, one can scarcely estimate what 
a valuable amount of scientific information would be 
gained concerning our anadromous fishes as they run up 
the stream to spawn and return to the lake again. Im- 
portant investigations could here very easily be made, 
and many valuable facts could be gained by such inves- 
tigations properly conducted. Until trained investiga- 
tors give our legislators many facts not now known, 
laws that will prove effectual in the protection and 
maintenance of fish or game can not be enacted. 
For example, the laws for the protection of fish are 
in most cases based upon their spawning habits, and 
this is of course right; but no one can give or find cor- 
rect answers to the following questions for even one- 
fourth of the number of kinds of fish found here: 
Just when do they commence to spawn, and when 
is the spawning completed ? How long before spawning 
do they run up the streams, and how long after do they 
return to the lake or sea? Just what species find it 
necessary to run up the streams for spawning, and what 
remain in the lake? What is their food, and what their 
enemies and diseases at this most important time in the 
it do a great deal of good in removing the lampreys, 
which they may be able to definitely base plans and cal- 
( Arrow indicates direction of current.) or condition of all organs, and their food before, after, 
and during spawning? In what numbers do they run up the streams, and what 
proportions are males or females? What kind of nest do they build, and do both 
sexes take part in its construction? Which sex cares for the eggs, and which for the 
young, and how? And, how long do the young need or receive parental protection? 
All of these questions and many others that could be asked are of great impor- 
tance, but can never be answered except through some such careful investigations as 
