JANUARY Io, 1907] 
NATURE 
253 
but occur chiefly in the upper and middle water layers, 
being found during the daytime in greatest numbers 
about 50 fathoms below the surface. The inference 
is obvious that the female eels spawn on the bottom 
in the same or a neighbouring area to that in which 
the larve are taken. The highest point of larval 
development seems to occur in June; the Lepto- 
cephalus has then ceased to feed, and the next stage 
of its existence is a long, retrogressive metamor- 
phosis, during which it decreases in size in all 
dimensions, and gradually takes on the slender eel- 
like form. During the latter part of the metamor- 
phosis the larva, or elvers as they may now be called, 
become very active, and commence their great migra- 
tion towards the coast and the fresh waters in which 
they feed and grow. The whole process of meta- 
morphosis occupies about a year, and during this time 
the young eels take no food at ail. 
Schmidt has obtained information from localities 
all along the west coast of Europe, from Spain to 
Norway, as to the time of year when the young 
elvers first appear in the rivers, and the interesting 
fact comes out that the time of occurrence of the 
elvers on the different coasts depends, in the first 
place, on the distance from the deep water in the 
Atlantic where the eels spawn. On the coasts 
directly washed by the ocean the ascent into fresh 
water begins between September and December, or 
even in January or February, according to the dis- 
tance from the deep water, whilst on the coast of 
Denmark and in the inner Danish waters the elvers 
do not arrive until April and May. 
The whole story of the life of the common eel, as 
now made clear by these investigations, is one of the 
most fascinating which it has fallen to the lot of any 
naturalist to unravel. We can picture the great shoal 
of parent eels, the long journey from the inland 
waters ended, arriving at their proper spawning 
places in the deep Atlantic along the whole length 
of the European coast; the floating eggs gradually 
developing into transparent, deep-ribbon-shaped 
Leptocephali; the slow transformation to slender, 
active elvers; the vast multitude of elvers, foodless, 
their whole energy concentrated and spent in loco- 
motion only, moving steadily in towards the coast, 
entering the rivers of Ireland and of France, entrapped 
in the great funnel of the Severn’s mouth, pressing 
on through the English Channel and into the North 
Sea, a remnant only, when tribute has been paid to 
all the rivers by the way, reaching the fresh waters 
of Denmark and the Baltic coasts; and, finally, the 
feeding and growth of the eels all over the European 
continent in preparation for the return migration to 
the sea. 
There can be little doubt that this new knowledge 
of the life-history of the eel will lead to results of 
great practical value to the eel fisheries of Denmark. 
The fact that one large market for Danish eels is in 
London makes the question one of practical interest 
to this country also. In the first place, Schmidt 
points out that since Denmark and the Baltic de- 
pend for their supply of young eels upon the general 
European stock coming from the Atlantic, any pro- 
tection of the adult fish in Danish waters is quite 
uncalled for, since even if all the Danish and Baltic 
eels were caught, only an insignificant reduction in 
the number of eel larve in the deep waters of the 
Atlantic would result. In the second place, since the 
evidence seems to show that the main supply of young 
eels to the Baltic comes from elvers which have 
travelled through the English Channel, and not 
around the north of Scotland, only a remnant of the 
great shoal of migrating elvers reaches that coast, a 
view which is confirmed by the fact that in Danish 
NO. 1941, VOL. 75 | 
rivers no such immense runs of elvers are known as 
are found in the Severn or in the rivers along the 
Atlantic sea-board. It would seem ‘that whilst the 
latter rivers, owing to their geographical position 
and configuration, receive far more elvers than they 
are able to support, those of Denmark and the Baltic 
may have a deficient supply. Schmidt recommends, 
therefore, that elvers should be taken from the 
western rivers (elvers caught in large quantities in 
the Severn are sold at from 1d. to 2d. per pound, and 
one pound contains about 1500 individuals) and trans- 
ferred to the Danish rivers and to the Baltic, where 
they are wanted, and where there is room for them 
to grow into large eels. 
Lack of space precludes us from describing in the 
same detail as we have done for the plaice and the 
eel the work which is in progress in connection with 
the other food-fishes. Heincke’s report on the occur- 
rence and distribution of the eggs, larva, and various 
age-groups of the food-fishes in the North Sea 
(Rapports et Procés-Verbaux, vol. iii.), and the papers 
by Hjort and others on the life-history of the haddock 
and cod already referred to, clearly indicate results 
which may eventually be of even greater interest and 
importance than those described above. 
It seems impossible, after an impartial consideration 
of the volumes before us, to come to any other con- 
clusion than that the International Fishery Investi- 
gations are being conducted with marked energy and 
enthusiasm by all the countries engaging in them, 
and that the great conception of an international 
cooperation of men of science having for its object 
the acquirement of the knowledge necessary for the 
rational exploitation of the sea on a scientific basis is 
in a fair way to justify itself in the eyes of the 
world. 
NOTES. 
On Monday last the Duke of the Abruzzi delivered to 
a large audience in the Argentine Theatre at Rome a 
lecture on his expedition to Ruwenzori, and was awarded 
the gold medal of the Geographical Society of Italy. The 
King and Queen of Italy were present with their full Court, 
and the Diplomatic Corps and chief officers of State also 
attended. The lecture will be repeated at a special meet- 
ing of the Royal Geographical Society to be held at the 
Queen’s Hall, Langham Place, on Saturday, when the 
King and the Prince of Wales have signified their intention 
to be present. 
WE regret to announce that Mr. Cornelius O’Sullivan, 
F.R.S., known chiefly by his investigations on scientific 
aspects of brewing, died on January 8, in his sixty-sixth 
year. We regret also to learn of the death of Mr. T. R. 
Dallmeyer, head of the famous optical firm, and formerly 
president of the Royal Photographic Society. 
Major E. H. Hirrs, C.M.G., R.E., who 
appointed to inspect and report upon the survey depart- 
ments now working in the protectorates of British East 
Africa and Uganda, has just left England for Mombasa. 
On the completion of the above-mentioned work he will 
proceed to Colombo to make a similar inspection in 
Ceylon. 
has been 
A sew Government farm, to be devoted wholly to 
tobacco research, is to be opened, says the Pioneer Mail, 
in the Rangpur district of Bengal, which is believed to 
contain perhaps the most important tobacco-growing area 
in the whole of India, the climate and soil in certain parts 
of the district being admirably suited to the cultivation of 
the crop. 
