| Description Of Item | The article refers to how ‘the muscles of certain fishes have the power of producing a vibratory motion by contraction. This motion is the cause of the sounds which these fishes emit.’ References that the vibrations in the umbrinae and hippocampi are normal and physiological and not owing to a secondary nervous action. The vibrations of the muscles are strengthened by being transmitted to a pneumatic bladder, which increases their intensity. However, some of the acoustic phenomena emitted by hippocampi are the result of vibrations not intensified by the bladder; so that here there is an instance of muscular motion producing sounds in a vertebrate animal without the aid of any organic auxiliary. Female and male hippocampi having the faculty of emitting sound, and this faculty is most highly developed in the spawning season. By establishing the fact that the umbrinae consort in shoals and are possessed of voice, M Dufosse claims to have completed the evidence which Georges Cuvier had collected to prove that the species umbrina cyrrhosa is the same as that called by Aristotle Chromis. He also claims to have been the first to have discovered the third vesical membrane in the pneumatic bladder of the umbrina, which membrane he also discovered in three different species of Scienoids.
From the collection of Thomas Laycock.
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