The gun was fired eight feet, four feet, and three feet above the surface of the stream, which varied in breadth from eight to ten feet, and in depth from sixteen to nineteen inches. It was fired into the air and into the opposite bank (struck from four to two feet above the water) in a direct line above different fishes, lying either singly or in shoals from five to nine inches from the bottom in small pools or runs sixteen to nineteen inches deep. Care was taken to fire up stream, to prevent the trout being startled by the flash of the cartridge. In no case did the trout take the very least notice, or give any sign of having heard the explosion or felt the concussion of the shot on the opposite bank, composed on three occasions of alluvial soil and on two of rock. Never once did a fish move or go down: in fact, in one of the experiments over a single well-grown trout, the fish was rising again to the natural fly in less than thirty seconds after the discharge of the gun.[263] Aristotle almost certainly learnt dissection when young. His father belonged to the Asclepiads, an order of priest-physicians who are believed to have practised dissection and taught it to their children. The son’s extensive knowledge of the internal parts of mammals, birds, and fishes probably resulted from dissections. Mr. Lones names forty-nine animals and fishes which from the trustworthiness of the definite information imparted were (he holds) certainly dissected. Of these some five are fish. To the question whether Aristotle ever dissected the human body, the answer after examining the evidence available must, I think, be in the negative, for three reasons. First: after describing the external parts of the human body he states that the internal parts are less known than those of animals, and that we must, in order to describe them, examine the corresponding parts of animals which are most nearly related to man. Second: his many mistakes—such as in the position of the heart being above the lungs, the emptiness of the occiput, etc.—can hardly be casual slips made by one familiar with human dissection. The passage, however, in _Nat. Hist._, VII. 3, points distinctly to his having to some degree dissected the _fœtus_.