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BULLETIN OF THE UNITED STATES FISH COMMISSION. 
this species attacking fish, or taking other food in the adult state, the information will be 
very acceptable. Professor Gage has found transforming larvae the last of October, 
and full adults on the spawning-beds as early as the 26th of April. Their transforma- 
tion is doubtless completed before midwinter. 
Some very interesting “Notes on the spawning habits of the brook lamprey ( Petro - 
myzon wilderi) ” have been contributed by Bashford Dean and P. B. Sumner (N. Y. 
Ac. Sci., vol. xvi, December 9, 1897). The authors compare their dates with recorded 
dates for this region, and conclude that “the spawning season of our local (New York 
City) lamprey is thus found to be nearly a month earlier than at Cayuga Lake,” but 
to draw accurate conclusions dates in the same year should be compared. In 1897 the 
brook lamprey was found on beds here on April 30. This makes a difference of 14 
days instead of 30 days between New York City and this region. These two species 
of lampreys are apparently identical in places of spawning, habitat of larvee, and 
observed external appearances (i. e., specific determinations in the ammoccetes stage 
are impossible), but the brook lamprey spawns from one to two weeks earlier than the 
lake lamprey. 
Plate 10 shows one of the lake lampreys attached to a common white sucker 
( Catostomus commersonii), which is also pierced by lamprey marks near both its 
ventral and pelvic fins, the body-wall being entirely cut through by these blood- 
suckers, and the abdominal cavity penetrated. This illustration is from a photograph 
of fresh specimens, under water, taken with a vertical camera, by Prof. S. H. Cage, 
at Cornell University. Professor Gage and Dr. Wilder have done more work with 
the lampreys of this region than have any other persons, and it is from Professor 
Gage’s article on “ The lake and brook lampreys of New York,” in the Wilder Quarter 
Century Book, 1893, that much information is taken for the present paper. The other 
illustrations are from photographs of specimens collected in Cayuga Lake or its inlet 
by persons at Cornell University, and were made for the purpose of showing some 
special features of the habits of this enemy of our fishes. 
The lamprey is similar to the frog and most other amphibians in the fact that 
from the young stage to the adult it passes through a metamorphosis slightly compar- 
able with the change of a tadpole into a mature frog. Its full life-history, as deter- 
mined by Professor Gage, is, briefly, as follows : 
The adult passes about three years in the lake, living exclusively by sucking the 
blood from living fishes, most of which are good food-fish. In the springtime, about 
the middle of April, apparently, they start out independently from the various points 
of the lake, each one forsaking its prey and swimming vigorously or stealing a ride 
by attaching to the bottom of some boat moving in the right direction. On they go 
until the current of the inlet gives them the clue, and they follow it. Frequently, 
also, ordinary fishes bound on the same errand throng the streams, and then the lam- 
preys, with their inherent desire to be taken care of by the labor of others, fasten to 
the larger fishes and are carried along up the stream. It not infrequently occurs 
that from the natural inclination of the stream, or from some of man’s obstructions, 
there are rapids or dams to be surmounted. Nothing daunted, the lamprey swims up 
just as far as possible by a tremendous effort, grasping a stone or other object so that 
he can not be carried downstream again, rests for a while, and then, by a powerful 
bending and straightening of the serpentine body, a leap is made in the right direc- 
tion, and what is gained is saved by again fastening the mouth to a fixed object. 
