Hypertrophy and the dilatation of hollow organs require to be considered somewhat more at large.

Hypertrophy consists, as the term implies, in augmented nutrition, resulting in increase of mass, and generally also of volume. Long ere the term hypertrophy, and even the idea it conveys, were formally recognized in science, not only had the possibility of an increase of mass and volume without material destruction of texture been speculated upon, but the fact itself actually observed in every variety of organ. Even up to the present time, however, the recognition of this species of anomaly has been characterized by a great want of clearness and precision. It is reserved for the discrimination of the present generation, by a searching comparative inquiry, based upon a more familiar acquaintance with the normal relations of the structure and admixture of organs, and aided by the physical appliances now at our command, to make an important progressive step over this wide and fertile field.

1. Simple Augmented Nutrition

Simple Augmented Nutrition, the increment of mass and of volume, not dependent upon the accession of any element foreign to the organ concerned - true hypertrophy.

2. Anomalous Augmented Nutrition

The increase of mass and of volume is here founded upon the accession of matter alien to the organ concerned, be it formless blastema or determinate form-element. This anomalous matter, when uniformly incorporated with the texture of the organ, that is, received both betwixt and within the definite structural elements, manifests itself as infiltration of the parenchyma - false hypertrophy. It approximates closely to heterologous growth.

Such are the two sections into which, as a preliminary step, we would distinguish all the so-called hypertrophies. Each will, however, have to be specially considered in the sequel.

Widely as the two hypertrophies should appear to differ from each other, and little as, strictly speaking, the second series belongs hither, its consideration in this place will be found preferable as regards practical utility, and expedient for other weighty reasons.

(a.) From true hypertrophy to false there are insensible gradations, both qualitative and quantitative, and both forms may coexist in the same organ. Thus, augmentation of the fatty contents of the hepatic cells is, by the addition of free fat and by a change in the quality of the fat, exalted into a palpable heterologous process.

(b.) Between the two series there exists the common connecting link that both are based upon an anomaly of the crasis; that, provided no obvious local causes prevail, both are engendered by a peculiar, personal, more or less defined, morbid tendency of general nutrition.

Every organ is by nature susceptible of, and almost every one has with more or less of precision been described as actually found affected with, hypertrophy. This does not, however, now apply equally to both categories of hypertrophy - that of the areolar and of adipose tissues, and of the muscles, more especially the organic, commonly manifesting itself as true, that of the so-called parenchymatous organs still more commonly as false hypertrophy.