JANUARY 13, 1923] 
a number of stragglers remain there throughout the 
winter, appearing in the following spring as a I-group, 
sharply distinguished in point of size from the young 
fry of the O-group which have come into being mean- 
. 
. 
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Fic. 4.—European eel (Anguilla v vulgaris); western 
Atlantic (west of 50" long. W At Dana, June 1920. 
Showing limit between O-group and I-group. 
time (see Figs. 3 and 4). These specimens of the I-group, 
however, found in early summer west of 50° W. long., 
are comparatively few. The great majority, now 
measuring 50-60 mm., have, in the course of the winter, 
moved north-east and east, and are now in the central 
Atlantic, about as far as the longitude of the Azores, or 
even some distance farther east. In 
the following year again, by early 
summer, these larve have attained 
their full size, averaging about 
75 mm., and appear now, as a 
Il-group, off the western shores of 
Europe and far up in the Medi- 
terranean, having, in the latter case, 
passed in through the Straits of 
Gibraltar during the winter, or in the 
autumn. 
The retrograde metamorphosis of 
the full-grown larve takes place in 
the course of the autumn and winter. 
In the process, they become elvers, 
and in spring, being then three years 
old (the III-group) move up into fresh 
water, when the temperature of the 
latter permits. At this stage of 
development they resemble minia- 
ture eels (Fig. 5). “The average length 
is about 65 mm., but they have lost 
greatly in dimensionsand weight dur- 
ing metamorphosis, running no fewer 
than 1500 specimens to the pound. In 
England, it is more especially on the 
west coast, in the Bristol Channel, 
that the elvers ascend in very great 
quantities during the spring, the 
phenomenon being generally known among the in- 
habitants, who catch them for human consumption, or 
even for feeding pigs. The name “ elver,” too, comes 
from this part of the country. There are interesting 
accounts from Gloucester telling how, in March and 
April, fishermen stand in hundreds along the river banks, 
each with a hand net, fishing for elvers, and often | 
NO. 2776, VOL. 111] 
Lends 
NATURE 
Fic. A arg; an eel (Anguilla vulgaris) ; 
and I11-groups) in June . 
53 
making astonishingly large catches—a s bundredweight 
of fish per man in one night. Bearing in mind the fact 
that 1500 elvers go to the pound weight, it will be 
realised that enormous quantities of eel fry must come 
in every year to the coasts of Europe from the Atlantic, 
numbers answering well to the great masses of tiny 
larve we found with the Dana on the breeding grounds 
of the eel in the western Atlantic. In 1920, 1921 and 
1922, we found first-year larve (O-group) of the re- 
spective years on those grounds, but at this present 
time of writing (October 1922), none of these will yet 
have reached their destination, the fresh waters of 
Europe. Not until next spring (1923) will the fisher- 
men of the Bristol Channel be able to catch elvers of 
the 1920 stock, which appeared in our nets in the 
western Atlantic in June 1920, and are shown in soit 2. 
And not until 24 years from now—that is to say, 
the spring of 1925—will the 1922-year class, specimens 
of which were taken by the Dana expedition about 
six months ago (April and May 1922) near Bermuda, 
make their entry into the Severn. 
Moving eastward, then, across the Atlantic, the eel 
fry come to the shores of Europe, and it is natural that 
here they should be found in greatest numbers. It is 
here also, that the capture of them has developed into 
an actual industry, as for example, apart from the 
Bristol Channel, also at several places in the south-west 
of Ireland, but especially on the west coast of France 
and the northern shores of Spain. They are taken here 


showing the size of the four youngest year-classes 
slightly enlarged: the top specimen measures 25 mm, in 
in tons, and the inhabitants have special names for 
them (civelles or pibales in France, and angulas in Spain). 
It must not be imagined, however, that all the eel 
fry coming from the Atlantic will be stopped by the 
west coasts of Europe. Great numbers of them continue 
Also at some places in the western Mediterranean on the west coast of 
Ite ie the elver fishery reaches the status of an industry in itself. 
