208 



Part III. — -Thirteenth Annual Report 



fisheries, lie arrives at the conclusion that the route taken by the eels 

 during their migrations along the coast can easily be recognised from the 

 position of these fisheries. It appears that the eels, after having avoided 

 certain portions of the Swedish coast, such as the coast of Sodermanland, 

 ifec, cross from the Cape of Falsterbo towards the Danish coast, and do 

 not again approach the Swedish coast till they have reached the narrowest 

 part of the Sound near Helsingborg. That the eels migrate along the 

 coast is proved by the position in which the fishing apparatus or 1 hommor ' 

 has to be placed, if the fisheries are to be successful. On the East coast 

 the 1 hommor ' are placed in such a manner that the eels have to enter 

 them from the North, while on the South coast the fish have to enter 

 them from the East, and in the Sound from the South. On the Danish 

 coasts, in the Great and Little Belts, the eels coming from the East and 

 South as likewise reported to wander in a north-westerly direction towards 

 the Kattegat. The time when the eel-fisheries are carried on along the 

 Swedish coast corroborates the supposition of the migration along the coast 

 referred to above. These fisheries commence at Grissleham and Land fort 

 in July, in East Gothland and the Kalmar district towards the end of 

 July and last till October, while in Schonen the fisheries commence in 

 August, and do not yield many fish till September and October. At 

 Humlebeck, on the Danish coast, about a mile from Elsinore, the eel- 

 fisheries commence towards the end of October, and do not come to a 

 close till the 10th of November. This shows that the ideas relative to 

 the migrations of the eel along the coast toward the Kattegat, expressed 

 above, are very probably correct. 



A comparison between the reproductive organs of the migrating eel, and 

 those of the eel at other seasons of the year, would naturally be expected 

 to afford conclusive proof that the migration of the eel is for the purpose 

 of spawning. This is only partially the case. Although, in some instances, 

 comparatively large ova have been found in the migrating eels, still none 

 of the migrating eels which have hitherto been examined have shown 

 any considerable advance in the development of the ovum. Benecke* 

 found that, in the earlier months of the year, the eggs were at the utmost 

 0*09 mm. in diameter. In September he found (on an average of numerous 

 measurements) a diameter of 0*10 mm. ; in October 0*16 mm. ; in Nov- 

 ember 0*1 8-0*23 mm., while the eggs showing other characters connected 

 with approaching maturity earlier in the season were not to be seen. 

 Mobius found in eels measuring from 48-70 cm., which he examined in 

 September 1884, October, November, and December 1885, and January 

 1886, that the greatest eggs measured 0*215 mm. On October 29th, 1885, 

 one eel measuring 53 cm., obtained from the Baltic, had ova 0*129 mm. 

 in diameter, while in January 1886, 3 eels, measuring 50-56 cm., which 

 had been caught in the Baltic in October 1885, and had been kept in a 

 box sunk in Kiel harbour, had ova measuring 0*198 mm. in diameter. 

 On February 9th, 1886, 4 eels from the box in Kiel harbour, measuring 

 52-60 cms., had ova 0*193 mm. in diameter ; 3 eels from Amrum, Feb. 2<J, 

 1885, which measured from 34-40 cm., had ova 0*086 mm. in diameter. 

 On March 5th, 1885, in two eels which were caught at Keitum, and which 

 measured 40 and 60 cms., the ova were found to measure 0*186 and 0*129 

 mm. respectively. Certain eels were placed in a sea aquarium of the 

 Physiological Institute of the University of Kiel, in October 1884. Of 

 these, one examined in May 1885 had large eggs of 0*215 mm., and 

 another, which died on June 13th, 1886, had ova of the diameter of 

 0*277 mm. He found that in the eels placed in the box in Kiel harbour 

 the ova did not increase in size, and that in January the ova had the 

 same diameter that they had in October. It is thus apparent, from the 

 * From article by Brown Goode, Loc. ext. 



