Auditory organs of a simple type are present in most insects.
Auditory bulla filled with honeycombed bony tissue.
At the fundus are placed the concrement-cells with their conspicuous otoliths (con) and the inconspicuous auditory cells, which are connected with the subumbral nerve - ring.
In connexion with the large size of the ears is the excessive inflation of the auditory bulla of the skull.
The pedal ganglia and auditory organs have disappeared with the foot, at all events have never been detected; the cerebral ganglia are very minute, while the parieto-splanchnic are well developed, and constitute the principal part of the nervous system.
The skull has a remarkably narrow and pointed muzzle and much inflated auditory bullae; while the two halves of the lower jaw are firmly welded together at their junction, thus effectually preventing the scissor-like action of the lower incisors distinctive of Macropus and its immediate allies.
In Bettongia, on the other hand, the head is shorter and wider, with smaller and more rounded ears, and more swollen auditory bullae.
The green gland and the structures associated with it in Decapods were at one time regarded as constituting an auditory apparatus.
In the majority of the Decapoda there is a saccular invagination of the integument in the basal segment of the antennular peduncle having on its inner surface " auditory " setae of the type just described.
When feathered or provided with secondary barbs the setae will respond to movements or vibrations in the surrounding water, and have been supposed to have an auditory function.
Thyng, who has carefully reviewed all the other theories, the balance of evidence tends to show that the quadrate has been taken up into the inner ear, where it is represented among the auditory ossicles by the incus.
2), says, " Krohn stated that the structures described by my father as ovaries were in reality salivary glands, also that the oviduct runs down to the orifice described in the Monograph of the Cirripedia as the auditory meatus."
In the members of the typical genus Potorous (formerly known as Hypsiprymnus) the head is long and slender, with the auditory bullae somewhat swollen; while the ridges on the first two premolars are few and perpendicular, and there are large vacuities on the palate.
Although no auditory organs have been found in the females, the song of the males is believed to serve as a sexual call.
By a simple modification, the open pit becomes a solid ectodermal ingrowth, just as in Teleostean fishes the hollow medullary tube, or the auditory pit of other vertebrate embryos, is formed at first as a solid cord of cells, which acquires a cavity secondarily.
From an evidential point of view the apparition is the most valuable class of death-warning, inasmuch as recognition is more difficult in the case of an auditory hallucination, even where it takes the form of spoken words; moreover, auditory hallucinations coinciding with deaths may be mere knocks, ringing of bells, &c.; tactile hallucinations are still more difficult of recognition; and the hallucinations of smell which are sometimes found as death-warnings rarely have anything to associate them specially with the dead person.
The South Australian Caloprymnus campestris represents a genus near akin to the last, but with the edge of the hairy border of the bare muzzle less emarginate in the middle line, still more swollen auditory bullae, very large and posterially expanded nasals and longer vacuities on the palate.
The list is completed by Aepyprymnus rufescens, which differs from all the others by the hairy muzzle, and the absence of inflation in the auditory bullae and of vacuities in the palate.
Gerbillus (or Tatera), with a large number of species, has a range coextensive with that of the sub-family; Pachyuromys, with two African species, has a short club-shaped tail and enormous auditory bullae; while the remaining members of the group, which are confined to North Africa, Eastern Europe and Asia, are arranged in the genera Meriones, Psainmomys and Rhombomys, the latter represented only by R.
The word is still sometimes employed in this sense, as of the ship's telegraph, by means of which orders are mechanically transmitted from the navigating bridge to the engine room, but when used without qualification it usually denotes telegraphic apparatus worked by electricity, whether the signals that express the words of the message are visual, auditory or written.
The skull, which must have consisted of hardened cartilage, exhibits pairs of nasal and auditory capsules, with a gill-apparatus below its hinder part, but no indications of ordinary jaws.
These are a chain of small bones belonging to the first four vertebrae, which are much modified, and connecting the air-bladder with the auditory organs.
Such hallucinations are commonly provoked by crystal-gazing, but auditory hallucinations may be caused by the use of a shell (shell-hearing), and the other senses are occasionally affected.
The tail and ears are generally very long; while, in correlation with the size of the latter, the auditory bullae of the skull are also large.
They have long hind limbs, large eyes and ears; and in correlation with the latter an enlarged auditory bulla to the skull, which is hollow and divided into a tympanic and a mastoid portion.
The air-bladder may be so reduced as to lose its hydrostatic function and become subservient to a sensory organ, its outer exposed surface being connected with the skin by a meatus between the bands of muscle, and conveying the thermobarometrical impressions to the auditory nerves.
One of the most puzzling features in its structure, and, at the same time, one of the greatest obstacles to the view that it is essentially primitive and not merely a degenerate creature, is the entire absence of the paired organs of special sense, olfactory, optic and auditory, which are so characteristic of the higher vertebrates.
Auditory ment in the crocodile, and with the ", chain " of Chicken, X 6 processus folii of the mammalian diameters; lateral and basal malleus, it follows that the whole views.
According to this theory, then, when a pure tone is received the auditory apparatus corresponding to that tone is most excited, but the apparatus on each side of it is also excited, though by a rapidly diminishing amount, as the interval increases.
The family, Chinchillidae, typified by the wellknown chinchilla, includes a small number of South American rodents with large ears and proportionately great auditory bullae in the skull, elongated hind-limbs, bushy tails, very soft fur and perfect clavicles.