3 22 THE POPULAR SCIENCE MONTHLY. 



that vast process of evolution whereby man is gradually brought into 

 fuller harmony with the universe he inhabits. There ueed, 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 disputa- 

 tion before King Darius were to be reenacted, 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 con- 

 quering from age to age." And the people as of old would say again 

 with one voice, "Truth is great, and prevails!" ' Advance-sheets 

 of MacmillarCs Magazine. 



-+*+- 



THE CHKOMIS PATEK-FAMTLIAS. 



By De. LOKTET. 



TP to the present we know but a small number of fishes which 

 vJ hatch their eggs and bring up their young in the cavity of the 

 mouth or among the gills. Agassiz, during his voyage on the Ama- 

 zonas, discovered one species. Afterward there was brought from 

 China the macroj)od, 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 laminae ; 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 be- 

 tween the tufts of reeds, the male approaches and takes them by in- 

 halation 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 laminae 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 1 Esdras iv. 41 : ney&Ki) 7) aXr)6ua, kgI i/7reprxk Magna* est Veritas, et pravalet. 



