Page:Proceedings of the Royal Society of London Vol 60.djvu/293

Rh nourishm ent w hatever. The resum ption of grow th was accompanied by a resum ption of feeding. Unfortunately, I had no other individuals of this stage.

The stage which I now pass on to describe can be obtained during the w inter in the sea. I have never found them at the m ouths of rivers. The length varies from 54 to 73 mm. Most individuals m easured about 65 mm. The body is relatively longer than in the elver. I t is also relatively deeper, as in Leptocephalus. We are reminded of Leptocephalus also by the pigm ent of the eye, the vitreous transparency of the body, th e sw im -bladder being indistinguishable in the living anim al, and the absence of all larval p ig ­ m entation. The blood is slightly coloured, and the bile is already green. S light pigm entation can be seen along the central nervous system, and at the m iddle p art of the caudal fin. This commencem ent of the definitive or adult pigm entation in th e regions nam ed before it occurs in any other p art is also seen in other Muraenoids. The definitive teeth are very m inute, and few in num ber. The intestine contains no food. A fter w hat I had observed in the other Muraenoids, the simple observation of the barely indicated teeth, and of the absence of alim ent in the gut, would have been sufficient to convince me th at the stage now under notice m ust be preceded by a Leptocephalus phase. Indeed, if we did not adm it such a preceding history, we could not understand how this little fish could have attained such a size w ithout acquiring well developed teeth, and w ith ­ out nourishing itself.

In conclusion, no one would hesitate, even not knowing Leptocephalus brevirostris,to refer the stage now under discussion to a Muraenoid about to complete its Leptocephalus m etam orphosis, were it not for the fact th a t there has been so much question concerning the reproduction of the Common Eel, and th a t so m any capable observers have failed in dealing w ith it, th at every new observation is received with scepticism. The stage of which I am now speaking, in the hands of a pure system atist, would probably be described as a Helmicthys, a genus established for certain forms of Leptocephali far advanced in transform ation.

The next forms to which I have to refer are captured in the course of migration from the sea into fresh water. W hen kept in an aquarium they assume the characters of the elver, dim inishing more or less in volume, and without nourishing themselves. The elvers of the Common Eel can present themselves in stages differing little from that last described, as well as in a form which has already developed the full pigm entation of the adult. Even those which most resemble the preceding stage always have a character which distinguishes them easily, namely, the presence of definitive pigment, more or less superficially placed on the head, and not to be