The lymphatic glands are abnormally enlarged in consequence of various conditions. We have here to consider more fully the anomalies induced in these structures by hypertrophy. This condition consists in an excessive accumulation of parenchyma between the lymphatics interspersed through the gland. In the present deficient state of our knowledge in reference to the structure of the lymphatic glands, and to the signification of their parenchyma, we must include under the above head all enlargements of the lymphatic glands which do not depend upon hyperaemia, inflammation, or any obvious secondary formation; although it cannot be doubted that by such a classification we are compelled to include with hypertrophies many specific alterations of the glandular parenchyma. We are as yet unacquainted with the mode of its origin, as well as with the manner in which the so-called lymphatic diathesis or habitus is induced, and with the exception of the little that is known in reference to hypertrophies generally, we are ignorant of the connection that may exist between the hypertrophied development of the lymphatic glands and the co-existing disturbances of the general organic system. We are inclined, from the little that is known in reference to the subject, to regard hypertrophy of the lymphatic glands as a secondary, symptomatic phenomenon, and not as a primary and substantive anomaly.

Hypertrophy of the lymphatic glands is most common in childhood, and until the full development of puberty; although it is not unfrequently exhibited after that period, and even in mature life. The lymphatic glands of the abdomen, of the mesentery, and of the lumbar plexus, are the most frequent seats of hypertrophy. This condition of the lymphatic glands of young persons is very commonly associated with a hypertro-phied development of other blood-forming glands, as, for instance, the thyroid gland, and more especially a highly developed spleen, obstructed involution of the thymus, a hypertrophied development of the follicular apparatus of the intestines, and hypertrophy of the nervous centres. Such hypertrophies either affect the whole system generally, or one portion especially, as, for instance, the glands of the abdomen.

Abnormal smallness is the result of atrophy. The lymphatic glands disappear in advanced age with the symptoms of general tabes, until their presence can scarcely be detected. This atrophy either affects the gland uniformly at all points, or preponderates at certain spots, where the parenchyma is entirely destroyed, leaving nothing but a white, soft, cellular, shrivelled tissue. The parenchyma which remains in diminished quantity, either at the periphery or in the centre, and presents either the appearance of a capsule or a central accumulation, very commonly acquires a dull, rusty-brown color. It is not improbable that the gland may first be reduced to the condition of a simple lymphatic nodule, as in its primary foetal state, and that the lymphatic vessels may also subsequently become atrophied together with the capillaries.

Moreover lymphatic glands may become secondarily atrophied in consequence of inflammation, and more especially of specific inflammatory processes. A marked degree of atrophy of this kind not unfrequently affects the mesenteric glands in consequence of typhous infiltration. The parenchyma of the gland is in this case absorbed, together with the product of the process. The involution of the typhoid mesenteric glands, which ultimately degenerates into tabes, has been fully considered under intestinal typhus. A similar atrophy occurs in adventitious products, partly in consequence of mechanical pressure and partly from inflammation in the neighborhood of the adventitious structure.