268 MR. T. SOUTHWELL ON THE REPRODUCTION OF THE COMMON EEL. 
Leptoceplialus brevirostris abounds from February to September. 
As to other months, we are in some uncertainty, because during 
them our only natural fisherman, the Orthagoriscus mola [in the 
intestine of which his chief supply of larvm were found], appears 
very rarely ; fifth, I am inclined to believe that the elvers 
ascending our rivers are already one year old, and I have observed 
that in an aquarium specimens of L. brevirostris can transform 
themselves into young elvers in one month’s time.” 
Thus through the indefatigable investigations of this talented 
Italian naturalist, the veil has at length been withdrawn from the 
obscure passages in the life-history of one of our most common 
fishes, much which was before unknown has been revealed, and 
much more that was only matter of conjecture has been verified. 
It may be interesting to know that Dr. Grassi had already 
highly distinguished himself by his investigations with regard to 
the life-history of certain species of Termites, and that his services 
to biological research have been recognised by the presentation of 
the Darwin Medal of the Royal Society. 
