If we consider the usual account of the sea-serpent, we find one constant feature, which seems entirely inconsistent with the belief that the creature can be a serpent. The animal has always shown a large portion of its length, from 20 to 60 feet, above the surface of the water, and without any evident signs of undulation, either vertically or horizontally. Now, apart from all zoological evidence, our knowledge of physical laws will not permit us to believe that the portion thus visible above the surface was propelled by the undulations of a portion concealed below the surface, unless this latter portion largely exceeded the former in bulk. A true fish does not swim for any length of time with any but a very small portion of its body above water; probably large eels never show even a head or fin above water for more than a few seconds when not at rest. Cetaceans, owing to the layers of blubber which float them up, remain often for a long time with a portion of their bulk out of the water, and the larger sort often swim long distances with the head and fore-part out of water. But, even then, the greater part of the creature’s bulk is under water, and the driving apparatus, the anterior fins and the mighty tail, are constantly under water (when the animal is urging its way horizontally, be it understood). A sea creature, in fact, whatever its nature, which keeps any considerable volume of its body out of water constantly, while travelling a long distance, must of necessity have a much greater volume all the time under water, and must have its propelling apparatus under water. Moreover, if the propulsion is not effected by fins, paddles, a great flat tail, or these combined, but by the undulations of the animal’s own body, then the part out of water must of necessity be affected by these undulations, unless it is very small in volume and length compared with the part under water. I assert both these points as matters depending on physical laws, and without fear that the best-informed zoologist can adduce any instances to the contrary. It is in fact physically impossible that such instances should exist.