Page:Proceedings of the Royal Society of London Vol 60.djvu/287

Rh dispel in the most im portant points the great m ystery which has hitherto surrounded the reproduction and the developm ent of th e Common Eel ( Anguilla vulgaris). W hen I reflect th a t this m ystery has occupied the attention of naturalists since the days of A ristotle it seems to me th a t a short ex tract of my work is perhaps not unworthy to be presented to the Royal Society of London, leaving aside, how ­ ever, for the present, the m orphological p art of m y results.

The most salient fact discovered by me is th a t a fish, which hitherto was known as Leptocephalusis the larva of th e Anguilla vulgaris.

Before giving the proofs of this conclusion I m ust prem ise th at the other Muramoids undergo a sim ilar m etam orphosis. Thus, 1 have been able to prove th a t the Leptocephalus stenops (Bellotti^, fo r the greatest part, and also the Leptocephalus and punctatus belong to the cycle of evolution of Conger vulgaris th a t the Leptocephalus hceclceli,yarrelli, bibroni,gegenbauri, kdllikeri, and many others im perfectly described by Facciola, and a p art of the abovenamed Leptocephalus stenops of Bellotti, belong to the cycle of evolution of Congromurcena mystax; th a t th e Leptocephalus tcenia ornatus and diaphanus belong to th at of Congromurcena th at under the name of Leptocephalus hefersteini are confounded the larvae of various species of the genus Ophichthys; th at the Leptocephalus longirostms and the Hyoprorus messanensis are the larvae of Ndtastomamelanurum,and th a t the Leptocephalus oxyrhynchus and o er new forms are larvae of Saurenchehjs cancrivora, and th at finally a new little Leptocephalus is the larva of Murcena helena.

The form known as Tylurus belongs to Oxystoma, of which we unfortunately know nothing more than a figure by Raffinesque 1 l V6w u ^ 1 ^ to find the LePtocePhalus of Myrus, of w uc i I have had only a single young individual, in w hich the transc e X t r o ^ O W y ia r f TanCed' Neither haTe 1 f0Und tho ^ P 40- cephalus oi Chlopsis hcolor, a very rare form, which is related to theTamilv'of th MurniclthysAs the result of these observations, the family of the Leptocephalid® has been definitely suppressed bv o 7 t L e t r sT j = i £ « “ * * * — t r v t ab° Ve-nam edspecies’ th eco n - t h r i r s w r ^ 0™? 1,; 1 ha the various stages in all b l T e h t T 7 b T b aV6 mad° *he du6 all changes brought about by the metamorphosis at the close of larval life.

Secondly, nationaU ta/e’s” 1111™1 1 f°Und nat,Ire a11 the re q"ired transitional stages.

Thirdly, experimental. I have fd,iow° d’