Other Changes Suffered By Blastemata

Other Changes Suffered By Blastemata, either in their primitive state, or after having attained to different stages of development, are:

1. Resolution into a molecular point-mass. Blastema breaks up, in its primitive state, owing either to positive intrinsic relations, or to the absence of compulsory extrinsic conditions for its evolution. Or, again, it breaks up, after having already entered upon a course of development, owing to the cessation of the external conditions necessary to its maintenance and further elaboration.

In the state of disintegration, it may undergo complete or partial resorption, with or without entailing constitutional mischief. This process is often attended with cretaceous deposition, often with fatty conversion of the protein-substances.

2. The blastemata stop short at different stages, retrograde, and perish. This may happen at any epoch of their development, from the primitive state upwards. The causes may be either inherent in, or extrinsical to, the blastema. In some instances it is a natural death, certain elements, epidermis-cells, for instance, dying off, after having attained their highest development. This of course applies more especially to solid blastemata. In their primitive condition, they part with their water, condense, and shrink into horn-like masses, and frequently ossify. When more advanced in their development, - for example, to fibre - such elements waste, and become reduced to primitive amorphous blastema, which immediately shrivels, often disengaging calcareous salts, that is, ossifying. Within the cell there occurs incrustation, with amorphous granules (a kind of granule-cells), or in stratiform deposition. Here the blastema has become bereft of all faculty for further development.

3. Conversion into fat, occurs both in primitive blastema and in tissues, and it is frequently accompanied by the disengagement of salts of lime, - by cretefaction and ossification. The protein substances undergo a transformation into free fat in little molecules, and into cholesterine crystals. To this conversion both solid and liquid blastemata are liable. Where cells exist, it occurs in the shape of granule-cells.

Vogel describes it as a peculiar granule-cell development, established for the resorption of an inflammatory exudation. "The exudation," says he, "is converted into nucleated cells of 1/300th to 1/100th of a millimetre in diameter. These cells progressively enlarge, until they have attained the size of from 1/80th to 1/60th of a millimetre, and gradually fill, at first with a few, afterwards with very numerous little dark granules, until the cell, originally transparent and colorless, becomes thoroughly opaque, assuming the brownish or blackish coloration of its contents, and appearing as an aggregation of granules, which cover and conceal the cell-nucleus, and frequently even the cell's walls".

The Concomitant Chemical Changes

The Concomitant Chemical Changes consist in the formation, or at least eduction, of a new (reckoning the cell's walls and the cell-nucleus, - of a third) substance within the granules, possessing the characters of fat, and occasionally of salts of lime. Vogel says, further on, " the matured granule-cells are not susceptible of ulterior organic development. After they have attained their full size, and filled with granule-cells, their further metamorphosis is a retrograde one. The cell-nuclei disappear, becoming, like the cell's walls, reabsorbed, whilst the granules, which alone remain, and are at first held together by a viscid medium, finally separate. After the complete breaking up of the granule-cells, the entire exudate originally present is converted into a semi-fluid, pulta-ceous mass, which, with the aid of the microscope, is found to consist of, as yet, unchanged granules out of the broken granule-cells, natant in a fluid, - the original serum of the exuded blood-plasma".

With reference to this process, which affects not alone inflammatory products, but every kind of blastema, we have additionally to state:

1. The process of granule-cell development consists not, we apprehend, in a development of fresh nucleated cells, and of granules within these. The granules become developed rather within the already existing cells, and also externally to them in the intercellular substance. There are seen distinct granules, which here and there collect in smaller or greater number, and occasionally assume an investment, not distinguishable from the bond-mass by which they are held together. Those developed within the cells accumulate and distend the cell's walls, until these give away and allow the granules to escape. This process may be directly witnessed, but it is further corroborated by the following circumstances:

(a.) Where the blastema is devoid of pre-existent cells, it does not contain any nucleated granule-cells either, but simply aggregates of granules; for example, in the fatty conversion of certain fibrinous coagula, of primitive muscle-fibrils, and of fibrous new growths.

(b.) The exudation-cell, the pus-cell, the cancer-cell, as the case may be, becomes the granule-cell, which retains the form of the pre-existent cell, - for example, the spherical, wedge-like, spindle-shaped, fibro-elon-gated granule-cell.

2. This process is, in point of fact, the fatty conversion of the contents of the cell. It is the counterpart of the fatty conversion of protein substances in every variety of blastema, and even in tissues generally. It gives rise to emulsive and saponaceous combinations, thus proving destructive to both blastemata and new growths, which latter it would indeed render fitted for resorption, were this not often hindered by the simultaneous disengagement of phosphate of lime with cholesterine crystals.

These changes run parallel with chemical ones, consisting in the development of different kinds of gluten, in horny conversion, and the like.

3. Finally, blastemata (like physiological textures) become reabsorbed at various stages of development, having become adapted for the process by a previous disintegration or fatty conversion, although, in the case of fluid blastemata, without any intermediate change. Solid blastemata may become gradually dissolved and fitted for resorption by blood serum percolating the textures, for example, in solid, fibrinous, inflammatory products. Occasionally some of their nuclei are left behind, presenting the only visible residue of comparatively extensive blastema masses.

Our next inquiry concerns the conditions which favor the throwing out of pathological blastemata in particular localities. These may consist in an exudatory process, not differing from that which presides over the normal act of nutrition, or else in processes which, though akin to physiological, are, in strict parlance, pathological. Such are hyperemia, and inflammation in its numerous modifications. Again, blastemata become consolidated within the vascular system through the coagulation of fibrin, as metastases, or deposits.