"These specimens having had the cavity of the mouth and of the gills extended in an extraordinary manner, I was induced to examine the cause of it, when, to my great surprise, I found them filled with about twenty eggs, rather larger than an ordinary pea, perfectly uninjured, and with the embryos in a forward state of development. The specimens are males, from 6 to 7 inches long, and in each the stomach was almost empty. "Although the eggs might have been put into the mouth of the fish by their captor, this does not appear probable. On the other hand, it is a well-known fact that the American Siluroids take care of their progeny in various ways; and I have no doubt that in this species and in its allies the males carry the eggs in their mouths, depositing them in places of safety and removing them when they fear the approach of danger or disturbance." =The Unsymmetrical Eyes of Flounders.=--In the two great families of flounders and soles the head is unsymmetrically formed, the cranium being twisted and both eyes placed on the same side. The body is strongly compressed, and the side possessing the eyes is uppermost in all the actions of the fish. This upper side, whether right or left, is colored, while the eyeless side is white or very nearly so. It is well known that in the very young flounder the body rests upright in the water. After a little there is a tendency to turn to one side and the lower eye begins its migration to the other side, the interorbital bones or part of them moving before it. In most flounders the eye seems to move over the surface of the head, before the dorsal fin, or across the axil of its first ray. In the tropical genus _Platophrys_ the movement of the eye is most easily followed, as the species reach a larger size than do most flounders before the change takes place. The larva, while symmetrical, is in all cases transparent. [Illustration: FIG. 126.] [Illustration: FIG. 127. FIGS. 126, 127.--Larval stages of _Platophrys podas_, a flounder of the Mediterranean, showing the migration of the eye. (After Emery.)] In a recent study of the migration of the eye in the winter flounder (_Pseudopleuronectes americanus_) Mr. Stephen R. Williams reaches the following conclusions: 1. The young of _Limanda ferruginea_ (the rusty dab) are probably in the larval stage at the same time as those of _Pseudopleuronectes americanus_ (the winter flounder). 2. The recently hatched fish are symmetrical, except for the relative positions of the two optic nerves. 3. The first observed occurrence in preparation for metamorphosis in _P. americanus_ is the rapid resorption of the part of the supraorbital cartilage bar which lies in the path of the eye. 4. Correlated with this is an increase in distance between the eyes and the brain, caused by the growth of the facial cartilages. 5. The migrating eye moves through an arc of about 120 degrees.