They could not have been artificially jammed into the hollow wood, in that way, without injuring them. The fishermen say that this is the habit of the family; they are often found thus crowded into dead logs at the bottom of the river, making their nests as it were in the cavities of the wood.[73] _October 14th._—Mr. Agassiz has a corps of little boys engaged in catching the tiniest fishes, so insignificant in size that the regular fishermen, who can never be made to understand that a fish which is not good to eat can serve any useful purpose, always throw them away. Nevertheless, these are among the most instructive specimens for the ichthyologist, because they often reveal the relations not only between parent and offspring, but wider relations between different groups. Mr. Agassiz’s investigations on these little fish here have shown repeatedly that the young of some species resemble closely the adult of others. Such a fish, not more than half an inch long, was brought to him yesterday. It constitutes a new genus, Lymnobelus, and belongs to the bill-fish family, Scomberesoces, with Belone and others,—that long, narrow type, with a long beak, which has such a wide distribution over the world. In the Northern United States, as well as in the Mediterranean, it has a representative of the genus Scomberesox, in which the jaws of its long snout are gaping; in the Mediterranean, and almost everywhere in the temperate and torrid zones, Belones are found in which, on the contrary, the bill is closed; in Florida and on the Brazilian coast, as well as in the Pacific, species of Hemirhamphus occur in which the two jaws are unequal, the upper one being very short and the lower one enormously long, while the Amazonian bill-fish has a somewhat different cut of the bill from either of those mentioned above, though both jaws are very long, as in Belone. When, then, the young of this Amazonian species was brought to Mr. Agassiz, he naturally expected to find it like its parent. On the contrary, he found it far more like the species of Florida and the Brazilian coast, having the two jaws unequal, the upper one excessively short, the lower enormously long, showing that the Amazonian species, before taking on its own characteristic features, passes through a stage resembling the permanent adult condition of the Hemirhamphus. It is interesting to find that animals, which have their natural homes so far from each other that there is no possibility of any material connection between them, are yet so linked together by structural laws, that the development of one species should recall the adult form of another.[74] The story of the Acaras, the fish which carries its young in its mouth, grows daily more wonderful. This morning Mr. Agassiz was off before dawn, on a fishing excursion with Major Estolano, and returned with numerous specimens of a new species of that family. These specimens furnished a complete