The Lake and Brook Lampreys of New York 477 



protection of the ova. The larvae hatch in these nests, re- 

 main there till they are about 12 to 15 millimeters in length, 

 then they seek a sand bank in the concavity of the stream. 

 In this bank they remain until fully transformed and supplied 

 with horny teeth. They then leave the sandy covering and 

 lead a roving, parasitic life in the open waters of the lake 

 (Plate VII, VIII, pp. 441, 449). 



9. In its larval life the lamprey is not injurious to man, but 

 aids him by serving as bait for food fishes (p. 457). 



10. During adult life the lamprey is highly injurious, as it 

 preys upon food fishes. The lake lamprey is the more in- 

 jurious from its larger size, greater numbers and longer para- 

 sitic life (pp. 445, 457). 



11. The lakes could be easily freed from lampreys, by catch- 

 ing and destroying them when they are on their way to the 

 spawning grounds up the lake inlets (p. 461). 



12. The respiratory mechanism of the lamprey is very per- 

 fect at all stages. From the perfection and arrangement of 

 the branchial valves, the expired water is not re-inspired 

 (Plate VIII, pp. 463, 467). 



13. The blood-corpu.scles are of two kinds, white and red as 

 in most other vertebrates. 



14. The white blood-corpuscles are relatively more numer- 

 ous than in mammalian blood ; they are mostly smaller than 

 the red blood-corpuscles and exhibit active amoeboid move- 

 ments (Plate VIII. p. 471). 



15. The red blood-corpuscles are bi-concave, circular discs 

 as with mammalian blood-corpuscles, and like the mamma- 

 lian red blood-corpuscles those of the lamprey arrange them- 

 selves in rolls or rouleaux, (Plate VIII, p. 472). 



It is assumed throughout this paper that the lake lamprey is 

 a land-locked species which is a recent offshoot from the true 

 anadromous sea lampre)'. But for the very striking similarity, 

 a similarity amounting almost to specific identity with the sea 

 lamprey, one might be strongly inclined to the belief that the 

 lake lamprey is an original product of the lake waters and 

 has onl}' a remote relationship with the sea lamprey through 

 some primitive and common ancestor. On the other hand 

 it might be urged that as there is free communication between 



