It is curious to note that in Aristotle, who apparently was familiar with most, if not all, of the then existent methods, no mention, as far as I can recall, occurs of actual fishing, save his story of the fight and escape of a big Glanis.
He owed his knowledge largely to his intercourse with fishermen and his close acquaintance with the fish markets—a haunting of which in Mediterranean ports was, as in Naples it still is, productive of a liberal education from the numerous specimens displayed and the hundreds of vernacular names applied to them.
Contrast this with our British markets, where, despite our more favourable wealth of sea-harvest, the kinds on sale seldom exceed a score or so, and their vernacular names hardly reach half-a-hundred.
Granting, however, all the advantages accruing from such acquaintance[259] with fishers and fishmongers, it needed an Aristotle to produce a book of such keen observation and (generally) accurate conclusions as his Natural History: for be it remembered that this, when compared with the vast volume of his other works, is a mere by-product of his industry and intellect, thrown off probably in the few years of his banishment.
Little escaped his ken, or his pen.[260] At one moment he notes that neither hermaphroditism nor parthenogenesis are uncommon, at the next he deals with the senses in fish. The question whether fish do actually hear or do not hear, remains, comme les pauvres, always with us; it remains like Etna dormant for decades, suddenly to pour forth columns of print which lava-like scar the fair face of many a ream of paper.
Aristotle comes down flat-footed in his verdict: fishes (we read, IV. 8) in spite of having no visible auditory organs undoubtedly do hear; “for they are observed to run away from any loud noises like the rowing of a galley. Indeed some people dwelling near the sea affirm that of all living creatures the fish is the quickest of hearing.”
Space forbids my dwelling on the various theories as to whether the undoubted effect of their being disturbed by certain noises is attained by hearing proper, or by vibration acting on the surface part of the fish and communicating instantly with the internal ear.
Day’s summary of the question, still regarded after thirty years as fair and conclusive, even if attaching undue importance to the fontanelles, is as follows. “Hearing is developed in fish, and it is very remarkable how any diversity of opinion can exist as to their possessing this sense. The internal auditory apparatus is placed within the cranial cavity: its chief constituent parts are the labyrinth, which is composed of three semi-circular canals, and a vestibule, which latter expands into one or more sacs, where the ear bones or otoliths are lodged. A tympanum and tympanic cavity are absent. They possess fontanelles between the bones, forming the roof of the skull, which being closed by very thin bones or skin permit sounds from the surrounding water to be readily transmitted to the contiguous internal ears. But the chief mode in which hearing is carried on must be due to the surface of the fish being affected by vibration of the water, and the sounds are transmitted directly to the internal ear, or else by means of the air-bladder acting as a sounding drum.”[261]
It goes against the grain to differ with such a charmful and theme-ful author as Sir Herbert Maxwell. But his conclusion[262] that fish in Loch Ken were disturbed every time a shooting party half to three-quarters of a mile away discharged their guns cannot be reconciled with the experiments made by me in July 1918 to test the behaviour of trout, when guns were fired, not half a mile away, but quite close to them.
Three of us, all accustomed to watching fish, selected a narrow shallow burn in which the trout ran from fingerlings up to fish three or four years old. Each in turn fired the gun (an ordinary 12 bore C.F.), with the usual shooting charge of powder and No. 5 shot. At the first two trials only was the shot extracted, so as to eliminate any vibration set up by its striking the opposite bank. Two of us lying hidden in the grass observed from different spots.