"If the fostering care of this mouth-brooding fish is regarded as wonderful and singular, what should one then say, if another fish is spoken of which does not regard this kind of protection as sufficient, and which therefore causes its eggs to hatch outside the surface of the water. The exceedingly adorned and elegant _Phyrrhylima Filamentosa_ performs this masterpiece of truest love. With great dexerity [tr. note: sic] this fish darts from 5 to 7 cm. above the surface of the water and there fastens its eggs on the walls of the aquarium--usually in one corner. Even though one must and can preserve damp air by covering the aquarium, the spawn would nevertheless surely dry up, if the fish itself were not constantly concerned to keep the spawn damp by an extended bombardment of little drops of water. In the performance of this act the fish remains near the surface of the water and then by a quick upward movement of the fins of the tail it throws a drop of water upon the spawn in such an expert manner as is truly admirable. One must also keep in mind here that the spawn require from three to five days for hatching, and now one can understand what a huge task this little fish performs and what efforts are required. Later on the young hatch and then slide down the slick wall of the aquarium into their native element." (V. Schloemp in _"Blaetter fuer Aquarien und Terrarienkunde,"_ Stuttgart, Sept. 1913.) In all the domain of natural science there are no wonders more amazing than those of instinct. The subject is simply inexhaustible. Moreover, every animal is absolutely dependent on instinctively performed actions and habits. The life-story of many wasps, of the various ants,--someone has called the brain of the ant the most wonderful speck of protoplasm in the world,--and of the insects generally, is bound up with instincts that partly interlock marvellously with the life-story of plants, and which are, even viewed in themselves, the greatest wonders of creation. The questions insistently call for an answer: How could these instincts preserve the animal when they were still in an incipient, undeveloped state? How could they arise through natural selection (which is simply _accident,_ of course), at all? Darwin says that there are instincts "almost identically the same in animals so remote in the scale of Nature, that we cannot account for their similarity by inheritance from a common progenitor, and consequently must believe that they were independently acquired through natural selection." Again he says "Many instincts are so wonderful that their development will probably appear to the reader a difficulty sufficient to overcome my whole theory." And here, in the vernacular of the day, we would depose that Mr. Darwin _"said something."_ CHAPTER SEVEN. Heredity.