514 TRANSACTIONS OF SECTION D. 
the map gives us the explanation: Lake Ontario is nearest the sea from 
which the eels come, and in order to appear in the other lakes they must pass 
Niagara. The difficulties in doing that most probably are the main reasons 
for the decrease in number in the other lakes. 
Of no less interest is the statement that eels fished in Wisconsin in fresh 
water connected with the Mississippi must have penetrated more than 1000 
miles from the mouth of this river. Thus, eels can travel enormous distances 
even after they have entered the fresh water. 
We may return now to the question of the centre of production of the 
American eel. I have proved that the propagation of Anguilla vulgaris 
takes place in all the long stretch from the Ferés to the west coast of 
Morocco, and have described how the fry from the spawning places west of 
the British Isles and France, during and after metamorphosis, move east- 
wards, and how the eel-stock of all North-Eastern Europe is recruited 
from here. It is evident that the migrations of the fry, favoured by the 
direction of the current and by the extraordinarily long duration of the 
pelagic life, may be of a very surprising length, as shown by the distance 
from the interior of the Baltic, or from the northernmost Norway to the 
1000-méttre curve in the Atlantic west of Hurope. 
In the western part of the Atlantic we have to do with another but 
very closely related species, the A. chrysypa. We are not justified in 
presuming that its biological conditions are identical with those of the 
European species. But the facts at hand tend to show that they are very 
similar, and that the distribution must find a similar explanation. 
While many hundreds of the larval stages of A. vulgaris have been 
taken over this large territory, only three larvee of the American eel have 
up till now been found. One was taken at 38° 47! 20” N. lat., 72° 37/ W. 
long.; one at 38° 25/ N. lat., 72° 40’ W. long.; a third was found cast 
ashore on the Bermudas (September 1906). These three captures occurred 
just within, or near to, the region where the temperature in depths of 
1000 m. is the highest in the whole western part of the Atlantic. It is 
certainly not due to chance that the larve are found just here. Most 
probably the centre of the spawning-places must lie about 35° N. lat. and 
70° W. long. In assuming this to be the case, the distribution of the 
American eel to the West Indies, with Guiana, Mexico, and the United 
States offers no special peculiarities. More remarkable is its occurrence 
in Canada, Newfoundland, and Labrador, because the temperature in deep 
water outside the last-named countries is very low, only 2° to 3° in 
1000 m. depth. But when we remember the facts established for the 
European eel and consider the currents, we may see that there is probably 
no place in the world where such conditions exist for an effective passive 
transportation of pelagic organisms by the help of the sea-currents as 
just off the coast of the United States and northwards: that is to say, 
from the supposed centre of reproduction to off Canada and Newfoundland. 
A current chart gives here a maximum speed of no less than forty to eighty 
miles per day, while the minimum speed is from ten to fifteen miles. 
Probably, therefore, the young eels are able to go further in this direction 
than they would otherwise be able to do. If we compare the distances with 
those we know to be accomplished by European eels, they are by no means 
greater. The great abundance of eels in New Brunswick, Nova Scotia, and 
Prince Edward Island agrees well with this statement. 
We have also another method of testing the correctness of the suggested 
theory that the eel-stock of these northern lands is recruited from places 
much farther south. We may, as I have done for Kurope, examine the 
time of ascent of the ‘elvers’ in the different places in the United States, 
Canada, ete. Although the information here is far from being as complete 
as those for the European eel, it is sufficient to prove that the appearance 
of the young eels in the fresh water occurs earlier in the year farther 
