Prothorax

“ Prothorax still wider than in that species, the sides much rounded, widest behind the middle, the base deeply sinuate-emarginate; the hinder angles being much produced back and pointed, coloured testaceous to a pretty large extent. Elytra at the base narrower than prothorax, and tapering a little to the tip, where they are abruptly truncated, with the inner angle sloped away, so that their joint extremity is a little notched at the suture; the narrow hind edge pale testaceous. Abdomen with three dorsal segments uncovered and deflected, edged with pale pubescence ”

“ Worker. Length 21⁄2 lines. Black; the antennæ and legs ferruginous; the head and thorax rugose; the prothorax transverse, its anterior margin slightly curved, with the lateral angles produced forwards and very acute; the thorax narrowed to the metathorax, which is armed with two divergent acute spines. Abdomen velvety black and globose; the scale of the petiole produced laterally into long, bent, acute spines, which curve backwards to the shape of the abdomen. ”

“ The lateral angles of the anterior margin of the prothorax acute, the metathorax armed with two long acute spines. Abdomen heart-shaped, its apex acute.
Hab. Aru.
3. Crematogaster insularis. C. niger, lævis et nitidus; antennis tarsisque pallidè testaceis; thorace spinis duabus acutis armato.
Worker. Length 11⁄4 line. Black, smooth and shining; the vertex, thorax and nodes of the peduncle with an obscure ferruginous tinge; the antennæ, tarsi, and articulations of the legs pale rufo-testaceous; the spines which arm the metathorax stout, elongate, and acute, with their apex pale testaceous. ”

“ The males are very small, free-flying insects with the prothorax, mesothorax and elytra greatly reduced, the latter appearing as little, twisted strips, while the metathorax is relatively large, with its wings broad and capable of longitudinal folding. ”

“ Worker. Length 5 lines. Black and shiny, the legs obscurely ferruginous [Pg 143] as well as the mandibles; the head strongly and evenly striated longitudinally. The prothorax with a circular striation above; behind, the thorax is compressed, the sides being obliquely striated, the striæ uniting and crossing the central ridge of the thorax. The node of the petiole and basal segment of the abdomen with a curved striation, the second segment longitudinally striated and depressed at its base, which is smooth and shining ”

“ B, III, the Breast, or Sternum; (1) the Prothorax is below the shoulder and above the fore-leg; (2) the Meso-pleura is contiguous to the prothorax and the shoulder; here in the upper front corner is the "Stigma," a prominent respiratory orifice, below which the large Stigmatical Bristle may be found ”

“ If, as is sometimes the case, the difficulty proceeds from a relaxation of the diaphragm, with general sagging down of the thoracic and abdominal viscera, so as to draw upon the trachea, then treat the whole trunk tonically, using the B D current. Place the N. P. low on back of neck, and treat with P. P. over the abdomen and thorax, and especially all around the edge of the diaphragm—along the lower line of the false ribs. Treat with medium strength of current, ten minutes, three times a week. The aim is to contract all the relaxed parts, so to relieve the larynx from the strain upon it. ”

“ Thorax sprinkled with white pubescence above, the sides more thickly clothed with the same; above, the thorax is transversely rugose, on the metathorax becoming more regularly striate; the metathorax has a central longitudinal carina and also one on each side; the legs sprinkled with erect white hairs; the tarsi pale rufo-testaceous with the claw-joint black; wings subhyaline, with a broad light-fuscous stain along the centre of the anterior pair; a hyaline streak crosses them at the base of the stigma. Abdomen: the petiole as long as the thorax, narrowest at the base of the abdomen ”

“ Whenever the excitement, producing hydrothorax, is idiopathic and independent of an organic disease of the lungs, heart, &c. its remote causes may be either of a general or local kind; and are the same which produce, when applied in a higher degree, or under different states of the system, the other forms of inflammation. The effusion may take place in those cases in which, the individual being predisposed, the inflammation, owing to some peculiarity in the cause, does not reach beyond its lowest grade ”

“ The two lungs must, therefore, be alternately affected as to their capacity according as the heart occupies space on either side of the thorax. In expiration, the heart, E, is more uncovered by the shelving edges of the lungs than in inspiration. In pneumothorax of either of the pleural sacs the air compresses the lung, pushes the heart from its normal position, and the space which the air occupies in the pleura yields a clear hollow sound on percussion, whilst, by the ear or stethoscope applied to a corresponding part of the thoracic walls, we discover the absence of the respiratory murmur. ”

“ The irritating effects of gas, unless it comes in small quantities through the ribs from wounds in the chest-walls, are very frequently followed in a short time by the production of a quantity of serosity or of pus. If air is introduced into the pleural cavity from perforation of the lung, there is also liquid matter from the lungs of such a character as at once to provoke inflammatory action. Such a condition is then denominated hydro-pneumothorax or pyo-pneumothorax. The latter was, in fact, recognized by Hippocrates by the sign of succussion, though not so designated. ”

“ The lungs are freely suspended by the windpipe, and are distended by the atmospheric pressure in opposition to their elasticity. Consequently, an opening in the walls of the thorax is liable to produce suffocation, by giving the air a more direct and easy route to the vacuum of the chest than through the trachea and lungs.
A delicate membrane called the pleura closely invests the lungs, and is then reflected to line the cavity of the thorax. By the secretion of a serous fluid, it prevents friction, which would otherwise result from the constant movement. ”

“ Pneumothorax is the only pathologic condition associated with signs similar to those of expiratory, valve-like bronchial obstruction by a foreign body.
3. Partial bronchial obstruction by an object such as a nail allows air to pass to and fro with some degree of retardation, and impairs the drainage of the subjacent lung. Limitation of expansion will be found on the invaded side. The area below the foreign body will give an impaired percussion note. Breath-sounds are diminished in the area of dullness, and vocal resonance and fremitus are impaired. Rales are of great diagnostic import ”

“ Pneumothorax means an effusion of air and of the matter of a tubercular abscess from disease into the cavity of the chest, or from an injury or a wound in the lung. When pneumothorax is the consequence of disease of long standing, the patient may be sensible of a sudden pain, which does not abate, and which is accompanied by an equally sudden increase of the difficulty of breathing, for which he cannot account. ”

“ If the thorax be pierced from any point whatever, provided the instrument be directed towards a common centre, A, Plate 1, the lung will suffer lesion; for the heart is, almost completely, in the healthy living body, enveloped in the lungs. So true is it that all the costal region (the asternal as well as the sternal) is a pulmonary enclosure, that any instrument which pierces intercostal space must wound the lung.
As the sternal ribs degenerate into the “false” asternal or incomplete ribs from before, obliquely backward down to the last dorsal vertebra, so the thoracic space takes form. ”

“ If the air enters the pleura and takes the place of the pus, the chest remains enlarged. Indeed, it sometimes increases in size to such an extent as to cause suffocation unless the pus and gas are withdrawn. The valve made by the false membrane allowing the air to enter the cavity, but not to escape from it, causes the fluid to accumulate rapidly, and we have pneumothorax to a very painful degree. The diaphragm is pushed down, and, if the disease is on the right side, the liver is forced down, and descends to a level with the umbilicus. ”

“ In the thorax, the diaphragm can descend, and the lungs can without danger occupy less space when there is considerable fat exhaled in the mediastinum. This remark, applicable also to the serum, explains an important phenomenon in diseases, viz. that a very small quantity of fluid poured out upon the tunica arachnoides can disturb the functions of the brain, whilst a great effusion is unattended with danger in the abdomen or the thorax. ”

“ Peanut kernels and watermelon seeds and, rarely, other foreign bodies in the bronchi produce obstructive emphysema of the invaded side. Fluoroscopy shows the diaphragm flattened, depressed and of less excursion on the invaded side; at the end of expiration, the heart and the mediastinal wall move over toward the uninvaded side and the invaded lung becomes less dense than the uninvaded lung, from the trapping of the air by the expiratory, valve-like effect of obliteration of the "forceps spaces" that during inspiration afford air ingress between the foreign body and the swollen bronchial wall. ”

“ Treatment, diuretic, tonic, derivative, thoracentesis, trochar and cannula or aspiration, point of election for puncture, method, asepsis, drainage by aspirator, or into an antiseptic solution, eligible cases, dangers attending thoracentesis, shock, rupture of false membranes and lung, infection of pleura, injection of antiseptics.
Hydrothorax or water in the chest is common to all domestic animals. It is as we have seen one of the most ordinary results of pleurisy, and may persist long after that disease has disappeared. ”

“ Though the lungs are closely applied to the costal sides at all times in the healthy state of these organs, still they slide freely within the thorax during the respiratory motions—forwards and backwards—over the serous pericardium, E, and upwards and downwards along the pleura costalis. The length of the adhesions which supervene upon pleuritis gives evidence of the extent of these motions. When the lung becomes in part solidified and impervious to the inspired air, the motions of the thoracic parietes opposite to the part are impeded. ”

“ The same observation applies to all the hemorrhages; they require means wholly opposite, according as they are active or passive; a remark moreover that is applicable to all diseases that have increased exhalations or secretions, whatever may be their seat. It is not the phenomenon that we are to resist, but the cause that has produced it. We diminish the forces, when serum is accumulated in the thorax, from a pleurisy; we increase them, when it accumulates from a disease of the heart, the lungs, &c. ”

“ Serum may accumulate in the pericardium, owing to an obstruction of the cardiac veins, caused by hypertrophy of the substance of the heart; and when from this cause the pericardium becomes much distended with fluid, the pressure of this upon the flaccid auricles and large venous trunks may give rise to general anasarca, to hydrothorax or ascites, either separate or co-existing. Tuberculous deposits in the lungs and scrofulous bronchial glands may cause obstructive pressure on the pulmonary veins, followed by effusion of either pus or serum into the pleural sac. ”

“ PATHOLOGICAL ANATOMY.—In traumatic pneumothorax and simple cases, such as from the bursting of emphysematous alveoli, the presence of air is the only pathological product. If the pleura and adjoining organs are not diseased, the rupture or tearing cicatrizes rapidly, and the air disappears in a few days by absorption. If a quantity of air be admitted, the pneumothorax may last for months; yet if the pleura is healthy, the air itself will not produce local changes. If blood or morbid products flow in with the air, then inflammatory changes occur, and we have deleterious products effused. ”

“ At the extreme periphery of the lung the danger is less, for the vessels are smaller and serious hemorrhage less probable, through the retention and decomposition of blood in small bronchi with later abscess formation is a contingency. The nature of the bridge of tissue is to be considered; should it be cicatricial, the result of prolonged inflammatory processes, it may be carefully excised without very great risk of serious complications. The blood vessels are diminished in size and number by the chronic productive inflammation, which more than offsets their lessened contractility. ”

“ And this is very serious in a patient whose respiration has already been much impeded, whose lungs are probably engorged, and who has certainly, by the mere existence of a wound in his trachea, lost the power of coughing properly; it must never be forgotten that a quantity of blood so trifling as to be at once ejected by a single cough in the case of a healthy chest, may be a fatal obstacle to respiration in one already weakened by disease. Thus any well-marked arterial hæmorrhage from cut branches, or from the isthmus of the thyroid, must certainly be arrested prior to opening the trachea. ”

“ The thorax, which they thus must always exactly fill, is a conical-shaped box, its walls being the ribs, and its floor a sheet of muscle known as the diaphragm. It contains, besides the lungs, only the heart and large bloodvessels. The problem, therefore, of drawing air into the lungs and (after the gaseous interchange described in Essay II., Section IV., has taken place) of expelling it again, becomes solely a matter of increasing and decreasing the capacity of the thorax. (See Diagram 34.) ”