THE HE PRODUCTION OF THE LAMPREY. 679 



ness, are deposited iu March or April. The adult fish gather themselves together in companies of 

 from ten to fifty individuals to spawn in water of little depth, where the current flows swiftly over 

 rough ground. In close proximity to each other they cling with their mouths to the bottom, and 

 their bodies streaming out iu the current squirming like the bodies of snakes. Every once in a 

 while the observer can see a malt-, easily recognizable by its size and black color, seize upon one of 

 the females with its suctorial mouth, and therewith firmly attaching itself to her close behind the 

 head. The two then extend themselves with a powerful backward squirm, and while the male, 

 with a half turn of its body, brings his abdominal aperture close to that of the female, a part of 

 her spawn may be seen flowing forth iu a clear, semi-opaque stream. This action is repeated 

 until the female has deposited all of her eggs. The young Lampreys, when hatched, burrow in the 

 mud. They require a period of four or five years before they attain th'e length of twenty centim- 

 eters." 



The development of the Lamprey is extremely remarkable. It was first worked out thoroughly 

 by Prof. August Miiller in ISSli. 1 The young was formerly considered to be a member of a distinct 

 genus, Ammocoetcs. The young of the brook Lamprey, P. planeri, which, in a general way, corre- 

 spond to those of other species, are thus described by Professor Benecke: "They are tawny yellow, 

 without any trace of silvery hues, and have half-moon shaped, toothless mouths, not intended for 

 suctorial uses. Their small eyes are hidden deeply under their thick skins, and hardly visible. 

 Their gill-openings lie in a deep furrow. The head is small and pointed, and the fins continuous." 



It is a curious fact that as early as 18G6 Leonhart Bolduer, of Strasbourg, investigated and 

 thoroughly understood the development and metamorphoses of the Lamprey, as is indicated iu the 

 following paragraph, translated from his work upon the water-birds, fishes, and other aquatic 

 animals of Strasbourg : 



" From August to December, Lampreys with eyes are not often seen and are rarely taken, but 

 blind Lampreys are found throughout the entire year. The Lampreys with eyes and the blind 

 Lampreys are all of the same kind, for the young from the very beginning are all blind, and bury 

 themselves at once in the mud as soon as they make their escape from the eggs. The blind 

 Lampreys develop no eggs until they develop their eyes." 2 



Like the eel, the Lamprey was formerly believed to be hermaphrodite. 3 



As far as I am aware, few observations are on record which indicate the date of the spawning 

 of the Lampreys in this country. P. niger spawns in early spring. Wittmack, in his excellent 

 work upon the "Fishery Statistics of Germany," states that P. marinus spawns at Hameln in June, 

 and in the Rhine, at Zurich, in March and April; P. fluviatilis in various parts of Northern Ger- 

 many, chiefly in March, April, May, and June, though in the Kurisches Haff also in November, 

 December, and February. In Bavaria their spawning season is from March to June; iu Austria 

 in April and May, and in Switzerland in March and April. P. planeri is said by the same author 

 to spawn in Pomerania in May; in the Rhine Provinces in March and April; in Hanover in May 

 and June; in Gotha in March and April, and in Lower Bavaria in May, June, and July; in the 

 Tyrol iu March, April, May, and June, and in Switerlaud in March and April. In the rivers of 

 Connecticut, where a lamprey fishery is still carried on, Lampreys are reported to be abundant in 

 May and June; and it is probable that these mouths are included within the period of spawning. 

 The artificial propagation of the Lamprey was first successfully accomplished on the 24th of May, 

 1879, when M. Fraueu, employed by the German Fishery Union in gathering sturgeon-eggs in 



MClAER: Arcliiv fur Naturgeschichte, 1856, p. IW5. 



S VON SIEBOLD: Susswassertisubo Mittelouropas, p. 378. 



3 SIR EDWARD HOMB iu Philosophical Transactions, 1815, p. 266. 



