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rumbling of a distant chariot, he may possibly exclaim, in the 
language of Catullus — 
u sonitu suopte 
Tintinant aures.”* 
Not so. Such sound is of a totally different kind. The sound in 
question is due to a vibration caused by the contraction of his 
temporals and masseters — those “aldermanic” muscles, as we 
believe they have been termed — and has been investigated by 
many observers, among them the celebrated Wollaston, and 
has in consequence received many names, e.g. Wollastonian 
vibration , Agitatio spiritum (Grimaldi), Bruit de rotation 
(Lsennec), Tremulation musculaire (Duges), &c. Wol- 
laston essayed to count the vibrations of these sounds, and found 
only from 14 to 36 in a second, so that they can hardly be re- 
garded as “ commensurable,” i. e. musical sounds, if Dupre’s 
recent conclusions be correct, that a sound composed of less 
than 32 vibrations per second cannot be appreciated musically. 
Now M. Dufosse has discovered that in many fishes the sounds 
produced by them are essentially of an analagous nature, and 
that the vibrations into which these may be analysed can be 
measured by appropriate instruments. Further than this, he 
has shown that there are two methods of the causation of such 
sounds — 1, by the contraction of muscles lying in close conti- 
guity to the air-bladder, so that the latter fulfils the office of an 
instrument of reinforcement of sound, in other words, a kind of 
sounding-board ; 2, by the contraction of muscles which are 
part and parcel of the air-bladder itself. So then this latter may 
be regarded in toto as an instrument of music, and not merely 
as playing a secondary role . The Mailed Gurnard, “ Marlamat ” 
( Trigla cataphracta , Linn.), offers a good instance of the first 
of these methods. In the abdomen of this fish, arched over by the 
ribs and lying within the so-called “ lateral ” muscles of Cuvier, 
may be seen on dither side a muscle ( i m, fig. 1) which runs 
along the whole length of this cavity. This muscle is attached 
posteriorly to certain fibrous internal aponeueroses, and, after in- 
creasing in size and becoming cylindrical anteriorly, splits into 
two slips, the shorter of which is attached by a tendon to the 
so-called “ humeral ” element of the pectoral fin ( h , fig. 1 ), while 
the other terminates at the back of the skull. These muscles 
are further conspicuous by their red colour, have moreover the 
characters of voluntary muscles, in that their ultimate fibrils 
are transversely striped, and are supplied by special branches 
from the third pair of cervical nerves (/3, 7, fig. 1) — nerves 
which in other gurnards pass to the u intrinsic ” muscles (?', m, 
* “ Upon my ear a noisy nothing rings.’ — Keats ( JEndymion ). 
(3 oixfitvoiv S’ atcoai uoi. — Sappho. 
