TRANSACTIONS OF SBCTION D. : 515 
south: that is to say, earlier in the places adjacent to the supposed 
spawning-place. (The time of appearance extends, as in Europe, over 
a period of several months; in this region from the earliest spring to 
the autumn, but somewhat later in the year in Europe.) 
Besides, the assumed situation of the spawning-centre agrees pretty well 
with the ‘density of eels’ observed in the United States. As we have 
seen, the eastern region, north of Florida, yields about 98 per cent. of the 
whole eel-production of the States. And of the eastern region, again, the 
part between Cape Hatteras and Cape Cod—a distance of only about 
450 miles—-yields by far the greatest portion. This part is situated only a 
little more to the north than the region where the warmest water is to 
be found in the depth. 
It is well known that the transplantation of several fresh-water fishes 
to foreign countries, where they formerly were not found, has often been 
attended with great success. American trout are transplanted to Europe, 
the salmon to Australia, ete. Also eels, and young eels, have long ago 
been transplanted successfully, and recently experiments in transferring 
yeung eels from the Bristol Channel to the Baltic have proved that these 
transplantations could be done on a much larger scale if the knowledge of 
the biological conditions of this fish be rightly used. 
In the case of eels, we must be clear as to whether we intend the trans- 
planted specimens to breed or only to grow in size. If we were to trans- 
plant young eels into the large rivers of South America or Western 
Africa, hoping that the eel would establish itself and multiply, we should 
certainly be disappointed. The utmost we might attain would be that 
these rivers proved to be suitable nurseries for the transplanted individuals. 
Transplanting experiments made in the United States on the Pacific Coast 
have been closely studied. Quite a number of transplanted fishes have 
become established, and by their fertility so numerous as to be of great 
importance for the fisheries—e.g., the shad (Clupea sapidissima), striped 
bass (Roccus lineatus), various carps (Cyprinus carpio and varieties), 
various species of salmon, cat-fish (Ameiurus sp.), etc. But the introduction 
of the eel proved to be a failure. In the first years after the introduction, 
a few eels were taken now and then; some of them seemed to have grown 
very quickly, perhaps owing to the favourable localities chosen for the 
experiments. But after the course of a few years the end came, without any 
fry appearing to replace and increase the stock set out. 
It may now he said beforehand that any repetition of these experiments 
will end in the same way, since whatever care is taken to procure the 
transplanted eels as favourable conditions as possible for their life and 
growth, no human power can obtain for them the conditions outside in the 
sea which they require for reproduction. 
It is quite another matter naturally, to consider it advantageous to plant 
out in the Western States a number of eel fry, with a view to later ‘ gather- 
ing in’ the same individuals when they are grown up, as is done at several 
places in Europe where the eel-fisheries are technically highly developed, or 
where the price for cels, sold in the living condition, is very high. 
4. On the Parallelism between the Nymphaline Genera Adelpha and 
Chlorippe. By F. A. Drxny, M.A., M.D. 
The two Central and South American genera, Adelpha and Chlorippe, 
present in many of their species a curious parallelism, several forms of the 
one genus bearing a striking resemblance to corresponding forms of the other. 
This is analogous with other instances, as of the Pierine genera Mylothris 
and Phrissura in Africa, where even the local races of the species of the one 
genus are closely followed in appearance by those of the other. , 
LL 
