— 196 — 



(6) do. 250 meters wire out (depth: 1310— 1330 meters) 2 hours 

 1 Leptocephalus brevirostris 

 Stat. 167. 57°4ö' N., 9°55 W., depth 1030—1310 meters [September 1st, 1905]. 



(1) Young-fish trawl, 300 meters wire out (depth: 1150 — 1160 meters) I'/z hours 



1 Leptocephalus brevirostris (in metamorphosis) 



(2) do. 300 meters wire out (depth: 1160— 1310 meters) 2 hours 



3 Leptocephalus brevirostris (in metamorphosis) 



(3) do. 300 meters wire out (depth: 1310—1175 meters) 3 hours 



1 Leptocephalus brevirostris (in metamorphosis) 



(4) do. 200 meters wire out (depth: 1175— 11 80 meters) 3 hours 



2 Leptocephahis brevirostris (in metamorphosis) 



(5) do. 250 meters wire out (depth: 1180 — 1030 meters) 3 hours 



1 Leptocephalus brevirostris (in metamorphosis) 



Leptocephalus brevirostris taken by the Irish investigation-steamer "Helga" 



(1) 50 miles W. 3/^ N. of Tearaght, depth: 411 fathoms [May 6th, 1905]. 



Tow-net on trawl 



1 Leptocephalus brevirostris (Stage l, length 65 mm.) 



(2) 54°59' N., io°53' W., depth: 7^ fathoms [November 18th, 1905]. 



Dip-net at the surface 



1 Leptocephalus brevirostris (end of Stage 4, length 77 mm.) 



5. Inward migration of the young eels from the Atlantic Ocean 

 to the coasts of West and North Europe 



a. General remarks on the phenomenon of ascent 

 It has been known for several centuries that small eel young appear in quantities on 

 the European coasts in the spring and move up into fresh water through rivers, streams 

 and other water-courses. Thus in 1667 the Italian Francesco Redi' states that over 3000 

 pounds of young eels were taken by some fishermen at Pisa on the river Arno in the 

 course of 5 hours, and from the description he gives of them, these were for the most 

 part quite tiny fry amongst which might be a few somewhat larger (up to 140 mm.). 

 The immigration of young eels has been observed in most European countries and de- 

 scribed a large number of times in many different languages. In several European coun- 

 tries these small eels migrating into fresh water go by special names. In Italy they are 

 called "montata" (from the verb montare — to mount). In France we find the same 

 word in "montée", which is the usual designation for the young eels on their way up 

 into fresh water, but various other names ^ are also used on the different French coasts. 

 In the provinces on the Mediterranean (Gard, Bouches-du-Rhône) they are called "bouirons" 



1 Francisci Redi, Opusculorum pars tertia sive de aninialculis vivis quae in corporibus animalium vivo- 

 rum reperiuntur, observationes. — Ex Etiusei Latinas fecit Petrus Coste, Lugd. Batav., 1729. p. 99. 



2 According to E. Moreau, Poissons de la France, III, p. 564 and L. Vaillant, Observations relatives 

 h la montée de l'Anguille sur les côtes de France (CR., t. CIX, 1889, p. 31 — 33). 



