These are the most important of all. They affect the solids and the fluids, especially the blood, in so far as certain form-elements enter as essential ingredients into its composition, and so far as this general source of nutrition, under particular circumstances, contains and supplies formative matter anomalous in many respects as to its embryonic character and primitive forms, and also as to all its ulterior stages of development. They are commonly connected, in the relation either of cause or of effect, with various other of the anomalies of volume, of consistence, of form and of color already discussed.

Every change of texture being founded in an anomaly of general nutrition, the proximate causes of this anomaly have to be investigated.

As such are directly demonstrable or at least deducible from analogy, - alterations of the blood, as the general fluid of nutrition, and anomalous character of the nutritive process itself. Accordingly, textural disease of the solids is in the one case the reflex of constitutional disease, in the other case a mere local ailment.

Quantitative anomalies of nutrition having been considered under the heads of hypertrophy and atrophy, the present chapter will comprise those textural diseases alone which depend upon qualitative anomalies of nutrition.

Textural diseases may be primitive arrests in the development of the texture - for example, in bones, in muscles, in pigment, - such as we may observe at any time in tissues adapted for regeneration. The majority are, however, acquired during intra-uterine, and more especially during extra-uterine life. In the former case the textural anomaly is congenital.

Textural anomalies manifest themselves -

1. As New Growths

The most numerous of the class.

2. As A Breaking Down Of Texture

The disruption involves both the primitive physiological and the new-formed pathological texture, - the latter, by their frequent persistence, at the embryonic stage of textural development, or even in the condition of the primitive rude blastema, are particularly predisposed to this sort of conversion of their elements. To this subdivision belong, besides the reduction of textures in atrophy - besides the breaking up of textures in genuine softening, in particular the liquefaction of textures in various processes of exudation, in suppuration, and in gangrene. And to these are yet to be added other processes which seem to be conversions of various complex substances constituting, now a rude blastema, now a definite texture, - the breaking up of fibrinous, albuminous blastemata, of muscular fibrils, of yellow artery-fibres, with conversion of their elements into fat, etc. They will be considered, together with their attendant circumstances, under the heads partly of general, partly of special anatomy.

New growths, as already observed, furnish forth the great majority of textural affections. For, apart from their mere local characters, almost all constitutional diseases are prone to localization and to the deposition, within an area more or less defined, of products in the shape of blastemata. Even the processes of liquefaction are in part ultimately reducible to a new growth, for example, to an exudation destructive of the texture, to the production of acid, etc. Textural diseases assuming the shape of new growths were formerly distinguished in a manner which here calls for a few remarks. Pathologists discriminated between:

1. Changes (metamorphoses) of textures.

2. Genuine new or heterologous growths.

With reference to this distinction which, before the adoption of the present auxiliary methods of research was highly estimated, we have to observe that, strictly speaking, the conversion of one texture into another only occurs in isolated instances, which will be hereafter specified. With these exceptions, all conversions are but seeming ones, and consist in the anomalous growth becoming developed betwixt the elementary particles and filling up the interstices of the original normal texture, so as to occasion the reduction and resorption of the latter.

This process of reduction and absorption may be so complete as ultimately to cause the original texture to be altogether replaced by the new growth, which now presents one uniform mass, corresponding in volume with the texture expelled, or even exceeding it, - in a word, constituting a tumor.

But although this process apparently disproves any conversion, it still remains matter for inquiry whether, in a certain sense, a conversion do not take place, - whether the original but reduced texture do not, under the determining influence of the heterologous development, furnish the blastema for the new growth? Several circumstances afford decisive evidence of a metamorphosis of this kind.

As true conversions are to be regarded -

(a.) The ossification of cartilages intended for permanent ones; as also of pathological cartilage - of certain euchondromata. Again;

(b.) The fibrillation of the hyaline intercellular substance of cartilage.

(e.) A metamorphosis of muscular fibre into areolar fibrils, such as takes place, in the organic muscles obviously through a splitting of the muscle fibres, - in the animal muscles, probably through fibrillation of the collapsed sheaths of the primitive muscle fibres, after the breaking up and resorption of their contents (the primitive fibrils).

(d.) A transformation of the organic muscle-fibres into the annulo-fibrous membrane-texture of arteries.

(e.) A transformation of primitive muscle-fibrils, of the fibrous web upon the layers constituting the annulo-fibrous membrane-texture of arteries, into free fat (see fatty degeneration). We are not indisposed to believe in a conversion of hepatic cells into the elementary cells of medullary cancer.

Let us, after this disquisition, turn to the division of new growths:

1. Into organized and organizable new growths.

2. Into unorganized new growths.