These spiracles, according to Hinds, are remarkable honeycomb-like structures, and perforations to the tracheal tubes have not been demonstrated.
At the receiving station electrical mechanisms record the signals once more as perforations in a paper strip forming an exact replica of the transmitting tape.
This received perforated tape is then used to control what is known as the printer or automatic typewriter, a machine that translates the tape perforations into letters and prints the messages in Roman type in page form.
When there is no current the shutter covers the perforations and no light passes, but when a current traverses the wires they are depressed by electromagnetic action, carrying the shutter with them, and a quantity of light proportional to the current strength is admitted through the perforations.
The record of the signals given by this instrument was an undulating line of fine perforations or spots, and the character and succession of the undulations were used to interpret the signals desired to be sent.
The arches bear on the convex outer side the delicate arborescent gills, and on the concave inner side develop a membranous septum with vermicular perforations, a special sifting or filtering contrivance through which the water absorbed by the mouth has to pass before reaching the respiratory organs of the branchial apparatus.
The structure formed by a number of such cells placed end to end is called a sieve-tube (obviously comparable with a xylem-vessel), and the end-wall or area of endwall occupied by a group of perforations, a sseve-plate.
When the sieve-tube has ceased to function and the protoplasm, slime strings, and callose have disappeared, the perforations through which the slime strings passed are left as relatively large holes, easily visible in some cases with low powers of the microscope, piercing the sieve.plate.
In some forms other gaps (perforations) appear in the vascular tube placing the pith and cortex in communication.
Dorsalwards into the peri - cardial sinus through fine perforations of its floor, and so makes its way into the heart again.
M' and m 2, Perforations of the diaphragm for the passage of muscles.
The mineral, crushed small enough to pass a sieve with perforations iu in.
Several modifications were proposed, in one of which, intended for the heating of non-conducting substances, the electrodes were passed horizontally through perforations in the upper part of the crucible walls, and the charge in the lower part of the crucible was heated by radiation.
The larvae of several nocturnal Lepidoptera feed upon the leaves of the willows, and the trunk of the sallow is often injured by the perforations of the lunar hornet sphinx (Trochilium crabroniforme).
The second series consists of circles each of which is formed of two sets of perforations, in the first circle arranged as 4:5, in the next as 3:4, then as 2:3, 3: 5, 4: 7.
In the outer series is a circle divided by perforations into four sets, the numbers of aliquot parts being as 3: 4: 5: 6, followed by others which we need not further refer to.
After 1/nth of a revolution, the two sets of perforations will again coincide, the lateral impulse of the air repeated, and hence the rapidity of rotation increased.
Now, it is evident that each coincidence of the perforations in the two plates is followed by a non-coincidence, during which the air-current is shut off, and that consequently, during each revolution of the upper plate, there occur n alternate passages and interceptions of the current.
Aquaticus) of the southern United States form the group Limnotragus, characterized by the harsher fur, the shorter ears, tail and hind-feet, and the complete fusion of the post-orbital process (which is so distinct in the typical hares) with the adjacent parts of the skull, so that neither notches nor perforations are developed in this region.
In Nereocystis and Macrocystis a zone of tubes occurs, which present the appearance of sieve-tubes even to the eventual obliteration of the perforations by a callus.
., cavities of adjacent coral `'` lites communicate by means of numerous perforations, which appear to represent solenia, and numerous transverse tab, ?
The surfaces are pitted all over with perforations of two kinds, viz.
The gas enters in the centre, and to make its escape again it has to pass into long wrought iron inverted troughs through perforations one-twentieth of an inch in diameter.
A constant flow of liquor is regulated through the washer, and the gas, in order to pass through the perforations, drives the liquor up into the troughs.