2688| 2240
4 || 6715| 5250| 2595| 450|| 6568|10041| 3686| 96|| 7108| 3009| 2138| 7543

From these researches we draw the following conclusions.

1. The spleen is not an indispensable, vitally important organ for the
guinea-pig, since that animal bears splenectomy without loss of health,
developes normally, and gains well in weight.

2. The hypertrophy and hyperplasia of the lymph glands, particularly of
the mesenteric glands, which develop after the operation correspond to a
=lymphocytosis=, which makes its appearance in the course of the first
year after the operation so constantly that it may be looked upon as a
=characteristic sign of the absence of the spleen=. This increase may
amount to double and more. We must therefore assume that the deficiency
of splenic function may be met by the lymphatic glandular system. This
period of lymphaemia may doubtless in some animals persist for years in
exceptional cases; in the majority, however, the lymphaemia diminishes in
the course of the first year, and indeed subnormal quantities of
lymphocytes may then be produced.

3. The cells of the bone-marrow, on the contrary, and the polynuclear
pseudoeosinophil cells do not show the least variation in the course of
the first year. Bearing in mind that under normal conditions these cells
are met with exclusively in the bone-marrow, and that inflammation in
animals after removal of the spleen is accompanied by an acute
pseudoeosinophil leucocytosis, exactly as in normal animals, one must
admit that the production and function of this kind of cell are quite
independent of the spleen. Hence there can be no doubt about their
myelogenic nature.

4. It is especially important that the mononuclear and the leucocytes
associated with them, undergo no increase. As these cells under normal
circumstances occur both in the spleen and in the bone-marrow, we must
assume that normally also the bone-marrow is responsible for the
majority of this kind in the blood, and that the deficiency in the
splenic contribution can be easily covered by a slightly raised activity
of the bone-marrow. Were the share of the spleen important, from
general biological considerations, an over-production of the kind of
cell in question must occur in the vicarious organs.

5. The increase of the eosinophil cells, which constantly makes its
appearance in the second year after the operation, is highly
interesting, and leads to a really enormous rise in their absolut