In the position of the Eustachian tube there is a passage, the spiracle (sp.
Just behind the eye is a smaller and more dorsal opening of the same kind, the spiracle (sp.
This suggests that the spiracleis really a somewhat modified gill slit.
In thespiracle is a miniature demibranch, the pseudo-branch.
First Thoracic Spiracle (left side), seen from the outside.
The first thoracic spiracle lies in front of the mesothorax, beneath the edge of the tergum; the second is similarly placed in front of the metathorax.
In Araneidæ, many Julidæ, and Peripatus each spiracle has a separate tracheal system of its own.
In the natural position this spiracle is set obliquely, the slit being inclined downwards and backwards.
The spiracles of the Cockroach are by no means of complicated structure, but their small size, and the differences between one spiracle and another, are difficulties which cost some pains to overcome.
The first abdominal spiracle is distinctly dorsal in position.
Four views of the First Abdominal Spiracle (left side).
In the first abdominal spiracle the setæ are developed only on that lip which carries the bow.
In the Scorpion, on each side of the four first ventral segments a spiracle may be discovered, which has no lip as in other insects, but is merely a circular orifice.
Generally there is a pair of spiracles to each segment, and in those insects that have a hypochondriack joint[199] there is often a spiracle in it.
In many of the Heteropterous Hemiptera in the parapleura there is an open spiracle without lips[191], to which, as in that beautiful bug Scutellera Stockeri, a channel sometimes leads.
No insect has any spiracle in the head; but in caterpillars and many other larvae there is a pair in the first segment of the trunk.
The lips are usually horizontal, but sometimes they dip so as to make the spiracle appear open.
There is a very visible spiracle over each of the four last legs of the Libellulina[195], but in the remainder of the Neuroptera Order they have eluded my search.
A spiracle therefore, speaking analogically, may be regarded in numerous cases as a mouth closed by lips.
These plates the animal can withdraw within the body, so as to prevent this spiracle from being stopped up by any greasy substance[210].
No, he breathes through his spiracle alone; and this is on the top of his head.
You would almost think a great gun had been discharged; and if you noticed the light wreath of vapour from the spiracle at his other extremity, you would think that that was the smoke from the touch-hole.
Spiracular disk with the dark markings less extensive; the mark of the lateral lobes not contiguous with the spiracle or the triangular area on the disk; dorsal marking indistinct or lacking.
No distinct spiracle in the stigmal plate on each side of the body.
With a distinctspiracle upon a stigmal plate on each side of the body (usually ventral) above the third or fourth coxae or a little behind (fig.
He believes that the blast was strong enough to blow a man off the spiracle if he were seated on it.
If the spiracle valve were in a condition to allow it to do so the animal would soon be drowned.
In this act of breathing the spiracle is normally brought above the water, the breath escapes, and the immediate inhalation is effected almost in silence.
B, Two segments of Scolopendra, showing the branching and anastomosing tracheae and a spiracle (sp).
The posterior extremity of the body is furnished with two curious appendages bearing a spiracle at the apex of each, which the larva frequently protrudes above the surface of the water.
In existing Crossopterygians the spiracle is a slit-like opening on the dorsal side of the head which can be opened or closed at will.
In many sharks and in sturgeons thespiracle forms a conspicuous opening just behind the eye.
In Dipneusti, as in the higher Teleostomes, the spiracle is found as an embryonic rudiment, but in this case it gives rise in the adult to a remarkable sense organ of problematical function.
You would almost think a great gun had been discharged; and if you noticed the light wreath of vapor from the spiracle at his other extremity, you would think that that was the smoke from the touch-hole.
A stage with a reduced spiracle does not proceed in development from a preceding stage in which the spiracle shows no reduction: it is reduced at its first appearance.
From each spiracle or breathing-pore there extends into the body a respiratory tube or trachea.
There is a spiracle near each ear in the first abdominal segment, and one on each side of the mesothorax near the insertion of the middle legs.
A few salamanders, while not possessing external gills when adult, have a spiracle or small circular opening in the side of the neck which leads into the throat.
In some of the sharks, and especially the rays, a spiracle or open foramen remains behind the eye.
Through this spiracle the rays breathe while lying on the bottom, thus avoiding the danger of introducing sand into their gills, as would be done if they breathed through the mouth.
In all four stages, spiracle persistent, and pigmentation resembling that of early stages.
In the wasps, under the spiracle of the metapnystega on each side, as in the Locusta, is what I also take to be a pneumatic pouch, which might easily be mistaken for a metaphragm.
