Page:Popular Science Monthly Volume 9.djvu/344

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THE POPULAR SCIENCE MONTHLY.

that vast process of evolution whereby man is gradually brought into fuller harmony with the universe he inhabits. There need, then, be no fear that the falling away of such artificial crutches as those whose history I have here been tracing should leave public truth maimed and halting. Upheld by the perfect fitting of the inner mind to the outer world, the progress of truth will be firmer and more majestic than in the ancient days. If, in time to come, the grand old disputation before King Darius were to be reënacted, to decide again the question, "What is the strongest of all things?" it would be said, as then, that "Truth abides, and is strong for evermore, living and conquering from age to age." And the people as of old would say again with one voice, "Truth is great, and prevails!"[1]Advance-sheets of Macmillan's Magazine.

 

THE CHROMIS PATER-FAMILIAS.
By Dr. LORTET.

UP to the present we know but a small number of fishes which hatch their eggs and bring up their young in the cavity of the mouth or among the gills. Agassiz, during his voyage on the Amazonas, discovered one species. Afterward there was brought from China the macropod, the singular habits of which are now known to all the world. All these species belong to the great group of the Labyrinthobranchiata; and Agassiz supposes that the fishes of this order only can hatch their eggs in so abnormal a manner, thanks to the branchial pockets which allow of the eggs being easily kept in place. But the Chromis, of which we give a faithful representation, proves the assertion of Agassiz to be erroneous. The Chromis pater-familias has the gills disposed in simple laminæ; it is unprovided with any special apparatus for retaining the eggs or the young ones, and yet it brings up about 200 young in the mouth and gills. It is always the male that performs these functions of incubation. After the female has deposited the eggs in a depression of the sand or between the tufts of reeds, the male approaches and takes them by inhalation into the cavity of the mouth. From there some movement, the mechanism of which we have not been able to observe, sends them between the leaflets of the gills. The pressure exerted on the eggs by the branchial laminæ suffices to keep them in place. There, in the midst of the organs of respiration, the eggs undergo all their metamorphoses. The young ones grow rapidly, and soon appear much inconvenienced in their narrow prison. They leave it, not by the gills but through the opening by which the bronchial cavity communicates with the

  1. Esdras iv. 41: μεγάλη ἠ ὰλήθεια, και ὕπερισχύει—Magnus est veritas, et pranalet.