I9 2 REPORT OF THE COMMISSIONERS OF 



soon to see each of these and kindred economic subjects fully studied, not only in 

 New York but also in other States, and proper remedies not only suggested by 

 economic zoologists, but speedily put into practical and effective operation. However, 

 economic application should be the end of all science, but that end should be final 

 and not initial. 



We cannot hope to be able to take practical steps toward making fish and game 

 more abundant until we know their habits and the full life history and habits of all 

 their enemies. This means an immense amount of field work for trained scientists 

 who will always keep the definite economic ends plainly in mind. 



Tl)e I^ampre^s. 



The necessity of a complete knowledge of the subject is so plainly shown in the 

 example of the lamprey that we here discuss it in detail. When we know as much 

 about any creature as we now know about the lamprey it will be possible for the 

 intelligent effort of mankind to avail in either increasing or reducing its numbers. 



What is a Lamprey f Lampreys are not fishes, but fish-like Vertebrates with no 

 paired fins, and neither spines nor bony rays in the fins which they do possess ; no 

 scales, no jointed appendages, and in fact no external appendages of any kind but the 

 vertical fins of the back and tail, with only one nostril, and that found on the middle 

 line of the head (see illustration No. 7) ; adults with a large circular suctorial mouth 

 armed with a great number of sharp chitinous teeth, but with no true jaws ; mouth 

 surrounded by a fleshy membrane which insures perfect suction and is fringed around 

 the entire margin with a close-set row of numerous fimbriae ; tongue rasp-like, con- 

 taining many sharp chitinous teeth ; larvae with a contracted mouth, screened by a 

 series of plates set at right angles to the entrance, forming a sieve ; two pairs of eyes 

 perfect and functional in the adult, imperfect, sub-dermal, and perhaps perceiving 

 only light in the larvae ; seven conspicuous holes (gill openings) in each side of the 

 neck; no bones whatever in the body, cartilage surrounding the brain, spinal cord and 

 respiratory chamber; breathing rapidly by means of the resiliency of the cartilaginous 

 network surrounding the cardiac region, and also by the contractility "of the attached 

 muscles ; purifying their rapidly circulating blood by means of gills, which are pro- 

 tected within gill pouches ; undergoing transformation or metamorphosis from the 

 larvae into the adults; feeding in the larval stage upon minute organisms (especially 

 diatoms) which live in the organic sediment beneath the water; adult representatives 

 of nearly all species feeding in the adult stage solely upon the blood of fishes (the 

 Brook Lamprey taking no food in the adult state); ascending streams to spawn; 

 building spawning beds with pebbles, pairing, spawning once, and then evidently dying. 



