The suprarenal capsules are occasionally deficient, especially when there is a deficiency in other organs also. They are not always absent in acephalous monstrosities; and as their absence generally involves the absence of numerous other organs, the fact suggests no distinct interpretation as to their functions. They are, moreover, generally present when one kidney is absent, and this proves that they are perfectly independent of the kidneys and the sexual organs (Meckel); their diseases place them in a more distinct relation with the lymphatic glands.

The fusion which often occurs in the kidneys is not found to take place in the suprarenal capsules.

Accessory suprarenal capsules, indicating an apparent excess of development, are of frequent occurrence. Several flattened acessory suprarenal capsules are then found in the renal and solar plexuses, and on the ganglion of the latter, varying in size from a millet- or hemp-seed to that of a pea.

They are occasionally of great magnitude, a circumstance which calls their foetal condition to mind, though it may result from morbid affections. On the other hand they may be small; and this may equally be the consequence of a congenital or an acquired anomaly. A reduction of size occurs in the shape of marasmus in advanced age, or at an earlier period of life; the organ shrivels up, becomes tough and coriaceous, its cortical substance assumes a dirty yellow color, its vascular medullary substance is obliterated; or in some cases it becomes friable, of the color of the lees of wine, or of a rusty brown, so as to resemble the spleen of old persons. The atrophy may also be the consequence of textural changes, appearing after inflammation in the shape of induration or obliteration.

The form of the suprarenal capsules is subject to various unimportant deviations; in reference to their position we have to remark, that they do not follow the congenital dislocations of the kidneys, but in these cases invariably retain their normal position.

Their textural diseases have hitherto met with little consideration. Hemorrhage not unfrequently occurs in them, on account of the vascularity of their medullary substance. The suprarenal capsule is found distended in proportion to the amount of extravasation caused by the rupture of a vein; and according to the period that has elapsed since the occurrence of the hemorrhage, we find the blood, more or less discolored and changed in constitution, enclosed within the cortical substance, which has become pale and atrophied, and is finally converted into a fibroid layer.

We scarcely ever have an opportunity of observing inflammation of the suprarenal capsules, except in its terminal stages, suppuration and induration. Some observers have found the suprarenal capsules converted into purulent pouches in the new-born infant, and even in the foetus (Andral).

The morbid growths not unfrequently seen, are: tubercle and cancerous degeneration; both, and particularly the latter, are found complicated with similar affections of other organs, and especially of the lymphatic glands.

Tubercle commonly appears deposited in the suprarenal capsules in large masses, and either fuses into pus enclosed in a callous sac, or is converted into a chalky concretion, invested by a fibroid tissue, in which all traces of the proper tissue of the organ have disappeared.

Cancer commonly appears in the form of medullary carcinoma, which very frequently involves the neighboring glands of the lumbar plexus, and the kidney, and causes a considerable enlargement of the suprarenal capsule. Hemorrhage occasionally takes place within the parenchyma of the cancerous growth, and causes it to be broken down into a chocolate-colored pulp.

It frequently happens that the suprarenal capsules become adherent to the kidneys in consequence of inflammation, or of other diseases associated with inflammatory reaction. A much rarer, though very interesting, occurrence is congenital union of the two organs, in which case one tunica albuginea invests the two, and the concave surface of the suprarenal capsule adheres to the kidney by means of short, tense, vascular, cellular tissue.