352 FISHES 



long teeth which projected beyond the mouth, and there can 

 be little or no doubt from the results of more recent investisra- 

 tions described below, that these larvae were Leptocephali. 



The Italian zoologist Grassi when he was professor at the 

 University of Catania, carried out in collaboration with Calan- 

 druccio, a thorough investigation of the numerous Leptocephali 

 of the Straits of Messina. By keeping specimens alive in aquaria, 

 as Delage had done so successfully in the case of the larva of 

 the conger, these Italian naturalists traced the development of 

 a whole series of Leptocephaline forms into different species 

 of the eel family, but the most interesting and most important 

 of their identifications was that of the larva of the common eel. 

 This discovery was made in 1893, an d the species of Lepto- 

 cephalus which was found to develop into the eel was one 

 named L. brevirostris, described by Kaup in 1865 in a catalogue 

 of the specimens in the British Museum. The distinguishing 

 characters of this form are its rather small size, not exceeding 

 8 cm. or 3 in. in length, its short snout, the number of segments, 

 not exceeding 118, the number of teeth, 14 in each jaw, and 

 the distinct tail-fin. It is noteworthy that the specimens ex- 

 amined by Kaup came from the Straits of Messina. 



Grassland Calandruccio obtained specimens of Leptocephali 

 in various ways, sometimes from fine-meshed nets used by 

 fishermen in shallow water near shore, sometimes from the sea- 

 shore where they found them stranded. In March, 1905, they 

 saw several thousand specimens which had been thrown up by 

 the waves near Faro. They also frequently obtained specimens 

 from the stomach of the sun-fish {Orthagoriscus 7/zo/a), which 

 they regard as naturally an inhabitant of deep water. They con- 

 cluded from their experience that the Leptocephali were naturally 

 hatched and developed at great depths, and were brought to 

 the surface or the shore by the strong currents and whirlpools 

 for which the Straits of Messina are famous. This view was 

 supported by the condition of the adult eels which they obtained 

 from time to time which, although not actually mature, were 

 certainly more advanced towards sexual maturity than ordinary 

 eels taken in fresh water. Their genital organs were more 

 developed, and in the males occasionally ripe spermatozoa 

 were found. Petersen in Denmark in 1894 had pointed out that 

 the eel when migrating to the sea and passing into the breeding 



