1. Textural Development. Organization

Solidified Blastemata, at their very development, either constitute various pure and unmingled new growths, or enter in the shape of intercellular substance, basement- and bond-mass, as the stroma into the composition of complex heterologous structures. Their development is, for the most part, foreshadowed in the types cast in the process of coagulation, and which were partly discussed in the foregoing chapter.

The principal abiding form-element that enters into the composition of new growths is the anastomosing, delicate fibrous network of consolidated fibrin. This, together with a hyaline intercellular substance, speckled throughout with shining nuclei, we have seen in old inflammatory indurations in the brain, as also composing an extensive fibrous cancer in the stomach.

Solid blastema either appears originally as a compact mass, or else takes up a considerable amount of moisture, and establishes a sort of skeleton-work with variously shaped gaps, offering a specific type of much interest. From a central mass, namely, arises a trelliswork, the rods of which are sometimes isolated, sometimes anastomose with each other, constituting a network with largish, and for the most part, oval meshes. This type characterizes in particular the opaque accumulations found upon the internal coat of arteries, as also certain fibrous tumors, especially when seated upon the dura mater. Or, again, solid blastema assumes the form of a membrane, either superficially spread out, or folded and rolled up in a tubular form, - a cylindrical fibre.

The blastema is here amorphous, laminated; or it presents upon laceration, a striated, fibrous aspect. It may assume, owing to the presence of elementary molecules, various degrees of opacity, or a granulated look; or it may display crystalline clearness. Lastly, it may or may not include nuclei and cells, in various proportions.

Solid blastema of each of the specified forms is worked out into fibres by splitting:

1. Either directly into areolar fibre and fibril, or else.

2. Into flat, riband-like, rough-surfaced, jagged, or into roundish, oval, mostly felt-like fibres, of from 1/100 to 1/85th of a millimetre in their broad diameter.

3. Into fibres perfectly identical with those of the organic muscles. By renewed splitting, for the most part commencing at their ends, the two latter kinds may give rise indirectly to areolar fibrillation.

Where there are nuclei present, engaged in the development into oblong nuclei, the splitting takes place in the direction of their longitudinal axis.

The Aforesaid Cylindrical Fibres

The Aforesaid Cylindrical Fibres represent little tubular bodies of from 1/100th to 1/10th of a millimetre in diameter, which end either in bulb-like dilatations, or in sharp points, frequently inosculate, and constitute a wide-meshed villous network. Their parietes are formed by a transparent, structureless, often wavy membrane, in a single or double fold. Their contents are elementary granules, - in hemorrhagic blastema, pigment-granules additionally, - nucleus formations, cells, together with an amphorous blastema in varying quantity. Cylindrical fibre at its parietes becomes areolar fibril, or perhaps this fibrillation is first developed in the blastema within the canal, as a delicately fibrous wave-curled axis-cylinder. Such fibres are commonly coincident with the primitive forms of blastema, more especially with the trelliswork described. We have frequently examined them, and we regard them as analogous with the cylindrical formations occurring in fluid blastemata (Engels germ-tubes.) Other kinds of fibre arise directly out of splitting, but more slowly, it would appear, and only after the blastema has entered upon essential chemical changes (as partial, glutinous, or horny conversion). They are characterized by their neutral relation to acetic acid, or at least by their stubborn resistance to its influence. Through progressive transitions they ultimately attain to uniformity with elastic and nucleus-fibre with which they further accord in blackness of outline, in solidity, and in elasticity. Of this nature are:

1. A transparent fibrillation for the most part solid, the fibre varying in diameter from that of the areolar fibril to one of undefinable minuteness.

2. A fibrillation in black outline, vibrating in lengthy deviations.

3. A twig-like fibrillation arising out of a short stem, with black contours.

4. A fibre-felt, resembling the intercellular substance of reticulated cartilage.

The Appearance In The Blastema Of Roundish Gaps

The Appearance In The Blastema Of Roundish Gaps, created by resorption, is likewise deserving of notice. In this manner solid masses of blastema acquire a porous, honeycombed aspect, whilst membranous blastemata become pierced or loopholed tunics. This does not, however, prevent the blastema either from remaining amorphous or from undergoing fibrillation. Amongst the elementary granules, nuclei, and cells which occur in various number in solid blastema, it is more especially the two former, and most frequently the nuclei, that undergo further elaboration.

1. Even in recent fibrinous coagula, within the vascular system, rodlike nucleus formations are discoverable. They enter into the composition of many delicately fibred textures.

2. The nucleus is developed through the oblong form to the caudated nucleus, and from thence directly into nucleus-fibre. Upon basement membranes, we often meet with serpentine, creeper-like nucleus-fibre stems. The caudated nuclei often constitute, when held together by an amphorous intercellular mass, - in rarer instances independently, - the fibrous element of not a few heterologous growths. More frequently, however, they enter singly into the composition of fibrous textures of other kinds.

3. Contiguous nuclei, in progess of fibrous development, conjoin and merge in the varicose nucleus-fibre, which by degrees acquires uniformity, and in rare instances forms the main component of fibrous new growths.

4. The nuclei form the basis of the true elastic splitting fibre. Elementary granules forming in collateral array, become confluent, and establish in various directions, more or less delicate, dark-looking, longitudinal, or reticulated fibres, which resist the influence of acetic acid. They are most conspicuous upon basement membranes.

In solid blastemata the elaboration of cells into fibre occurs, for the most part, slowly and in the ordinary routine. The majority of the cells, however, remain undeveloped, and become reabsorbed. Still the development of primary cells into parent-cells, however rare, does occasionally happen.