103 2 



SCANDIX AVIAN FISHES. 



ter. "And hero", says Vilu'msex", "it iiinv dt'tcn Ije 

 observed huw tlie ("od in winter disuorge tVoin their 

 crammed stoiiiachs extremely siiiali and seiin-ti'.-iuspa- 

 rent young Eels, only o — 8 em. long'. Food digests 

 rapidly in the stomach of a Cod, and as the disgorged 

 Eels are fresh and entire, we mav safely conclude that 

 they have heen swallowed (|uite recently and thus on 

 the spot. I have also seen them jum]) alive from the 

 jaws of the Cod, which had probablj^ seized them at 

 the same moment as it took the tisherman's bait. The 

 bottom in this part of the channel consists of mud 

 mixed with clay, and must be tenanted by multitudes 

 of Eel-fry, for sometimes every single Cod has secured 

 a number of them. It cannot well be assumed that 

 these frail creatures swim freely al)0ut u.t a time of 

 j-ear when tlie larger Eels eagerly take refuge in the 

 security of the bottom. It is more probable that they 

 lie concealed in the mud, but that the Cod knows how 

 to rout them out from their hiding-places. This opi- 

 nion is su})ported l)y tlic fact that the stomacli of the 

 Cod also contains other inhabitants of the mud, such as 

 Ascidians, Holothurians, worms, etc." 



"The Eel lays its eggs in the nuul", writes Des- 

 jiarest'', "after a kind of copulation. The eggs are bound 

 together b}' a slimy mass like that which envelops the 

 ova of the Perch, and form small clues or round balls. 

 Each female, as we have ascertained by personal ob- 

 servation, annually lays several of these agglomerations. 

 The fry are soon hatched, but remain for some davs 

 after exclusion within the said balls. When the fry 

 have attained a length of 4 — .5 cm.', they liberate them- 

 selves from the bonds that confine tliem, and ascend 

 the neighljouring ri\ers in dense and extremely nume- 

 rous bodies". 



Not all the Eel-frv, however, re|)aii' to the rivers 

 at tliis age. A great nundier pass one or two years 

 in the sea'', and are 2 — 4 dm. long when they under- 

 take the ascent. At Elfkarleby fry of this size make 

 their way up the Dal I'.lf, where thev are called AI- 



vlmmor or Alrinner\ without intermission from July 

 till October, but mostly in Sejitemlier. These Alvim- 

 mor or Elvers are the Cirelles of French rivers. When 

 thev have grown somewhat larger, and are found among 

 the seaweed of the littoral regions or the grass of the 

 lakes, they are known in S\\eden as Gras-cil oi-, on ac- 

 count of their watery flesh, Bh'it-nl, in Denmark as 

 Visse-(il. 



We have still to consider the (piestion whetlier the 

 Eel als(i breeds in fresh water. As wc liave seen, this 

 is hai'dly |)robable. Eels occur, it is true, in tarns of 

 great elevation and in isolated pieces of water which 

 seem to be cut off from the sea by barriers impassable 

 to a fish. But Eel-fry have an almost incredible capa- 

 citv of penetrating or circumventing obstacles in their 

 path, and their elders can also travel bv land. Obser- 

 vations lia\c l)een made, however, which are at least 

 easiest of explanation on the assumption that the Eel 

 propagates in fresh water as well as in salt'. Trvboii 

 states (1. c.) that "in 18()4 1,000 young Eels were trans- 

 planted from I'^lfkarleby to Lake Hagel in Dalecarlia. 

 Tile lake lias no outlet, and no Eels had previously 

 been found in its waters. In 1871 Eels weighing 1';^ 

 — I'/a kilo, were taken there, in 1872 specimens that 

 turned the scale at r7, 2, and even .3'4 kilo. In the 

 summer of 1879 small Eels weighing only '4 kilo, as 

 Avell as larger ones Avere caught. Eel-fr}' have been 

 planted in the lake on oidy one occasion". (_)nly a few 

 vears ago it was supposed tliat male Eels occur in the 

 sea alone, and do not ascend, at least not in any great 

 number, into fresh water. It was consequently incon- 

 ceivable that the Eel should multi])ly in fresh water. 

 But the collections of the Ro\'al ^luseum had contained 

 ever since 1844 a male Eel 23 cm. long, taken by 

 Lieutenant Robsahm at Trollhattan; and in 1880 Hek- 

 iiES'' found 13 male Eels in the Elbe off Cumlosen, near 

 Wittenberg, about 25 German miles from the mouth of 

 the river. Recently (the middle of June, 1S93) at 

 Silkesborg Papermills and Ilolm Mill, in the Eel-tra])S 



" Diiiisk. FiskeritidfiKle, 1892, i... IT.. 



* CiiENU, F.ncycl. <V[Iist. Nat., Jiept., Poiss., p. 328. 



'^ But cf. .Iacoby's staleuieiit, nientidiied nlxive, (liiit iridsl of the yoimg Eels ia\ tlu-ir iiiiwaril journey at Coiiiacchio are only — 8 

 mm. long. 



"^ In the old outlet of the Uiver Niss.i, the so-called Svinback, open towards the sea, but now almost choked up, Eel-fry ' j — 1 f''"- 

 long used to take up their summer quarters wilhout evincing any migratory tendencies; and the hoys of Halmstad amused themselves by 

 wading in the shallow water to frighten these young Eels out of the mud and cl.'iy ami catch them. 



" Su^^DEV.^LL, Stockli. L. Hush.-Sallsk. Handl. 1855, p. 92; Tktbom, Landthr. Akad. Hand!., Tidskr. 1S81, Oiii s. h. Alchiiier etc. 



■'' See for example Lewin's remarks in Wittmack, Deulsch. Fisch. Ver. Circular, No. 1 (1S75), p. 127. 



? BuU. U. S. Fish. Comm. 1881, p. 98, and Mitth. Sect. Kiist., Hochseef., Deutsch. Fisch. Ver., 1893, p. 113, not. 2. 



