The Formation Of Flesh-Granules is not decisive evidence of a bland, benignant pus. It may accompany, and even luxuriate under, the production of ichor. In the one case, however, the granulations are marked by their durability, and by their further textural development, whilst in the other, they form but to be corroded and redissolved by contact with the ichorous fluid.

Flesh-granulations accompanying the production of pus in or upon heterologous growths, have, for the most part, the significance of textural elements of such growths.

The tendency of pus (and of ichor) to vent itself externally, is commonly overrated. Pus deposits are often deeply encysted within organs and a passage to without often needs to be made artificially, in order to prevent the fluid from burrowing.

The assertion that extensive exudates are especially liable to become converted into pus, is ill founded, if magnitude of the exudate be the assumed condition of such conversion. Doubtless what led to the opinion, was the liquefaction of the commonly very massive croupous exudates, together with the circumstance that pus-blastema, either pure or combined with croupous fibrin, very often becomes effused in great quantity. Apart, however, from quantity, the puriform quality of an exudate is invariably due to inflammatory stasis. This alone, and not the quantity, can determine the development of the elements of pus.

Purulent and ichorous exudates are met with not alone in the localities assigned to normal pus. They often occur in great quantity upon serous and synovial membranes, and in areolar tissue, more especially the subcutaneous and submucous, as also in certain of the more lax, deep-seated collections of this tissue, for example, in the mediastina, in the posterior circumference of the caecum, around the rectum, and the like. Lastly, they take place upon mucous membranes, within soft parenchymata, and in bone.

The following are the metamorphoses which the said exudates, if not excreted, undergo:

(A.) Transformation Of Texture

Transformation Of Texture, appearing, after the process above described, in the form of so-called granulations.

(B.) Dissolution

Dissolution affects both the form-elements (cells, nuclei), and the fluid intercellular substance, in the shape of various unknown chemical transformations. Under this head may be brought the septic decompositions, suffered by these exudates under peculiar circumstances; for instance, through long stagnation, through contact with the atmosphere, through the effect of medicinal substances, and the like. These may cause the degradation of bland pus into ichor, and of ichor a step lower in the scale.

(C.) Fatty Conversion

Fatty Conversion in the formative process of granule-cells, frequently combined with the simultaneous deposition of the salts of lime, (cretefaction).

(D) Resorption

The manifold ways in which pus substantively, or as pus-serum, enters the circulation, and there occasions pyaemia, cannot at all concern us here. They were before adverted to, and will be further and more amply noticed under the head of Pyaemia.

Here we have to consider the resorption of pus in a more restricted sense, and irrespectively of pyaemia.

This resorption can apply only to the serum or plasma of pus. To pus or ichor in their totality, that is to say, their form-elements included, it can only apply after they have undergone liquefaction or fatty conversion. Upon the mode of liquefaction depends, in the case of pus, the nature of the consecutive phenomena. If it consist in a putrid decomposition, the noxious effects of septic poisoning of the bood may ensue.

Pus may either become completely reabsorbed, or leave within its former nidus a residue of fat in the shape of discrete or aggregate fat molecules and cholesterine crystals, within a glutinous fluid, or in the shape of chalk incrustation and concretion.

The depot of pus and of ichor (abscess) heals, through the subsidence of pus and ichor production, and through the organizable products of inflammation existing in the walls of the abscess, with new supplementary ones, undergoing transformation into vascularized textures. Pending this act, the contents of the depot are in the manner before specified, entirely or partially reabsorbed. According to the measure of resorption, the walls of the abscess shrink together and ultimately coalesce into a solid cicatrix, or else include an inspissated fatty or chalky, or lardo-cretaceous residue of the primitive contents.

Pus and ichor are the product, at one time of a mere local inflammatory stasis, at another time of a localized pre-existent crasis, namely, general pyaemia. In the latter case, the production is characterized by the rapidity of its occurrence.

Suppuration in open abscesses and upon granulating sores is peculiarly chronic in its course. This process manifests itself as a protracted stasis, communicated from the original textures to the embryonic new growths which the granulations with their newly acquired vascular apparatus have given rise to. Taken in another point of view, the granulations appear to stand to pus-formation in a relation which earlier pathologists signified by the terms pyogenous membrane, a pus-secreting apparatus.