ession of Uskoff, by a too rapid ageing of the
lymphocytes.

Further evidence for the origin of the lymphocytes of the blood from the
lymphatic glands is to be obtained from those cases in which we find an
increase of the lymphocytes in the blood. These "lymphocytoses" occur,
in comparison with other leucocytoses, relatively seldom. Under certain
conditions in which a hyperplasia of the lymphatic glandular apparatus
makes its appearance, we often see at first an increase of the
lymphocytes in the blood. Ehrlich and Karewski in some unpublished work
have investigated together a large number of typical cases of lymphoma
malignum, and were able constantly to observe a lymphocytosis, which in
some cases was of high degree and bore almost a leukaemic character.

Relying on these facts Ehrlich and Wassermann (_Dermatolog.
Zeitschr._ Vol. I., 1894) made the diagnosis _in vivo_ of
malignant lymphoma in a rare skin disease, chiefly from the
absolute increase of the lymphocytes alone, although no
swelling of the glands was palpable. The post-mortem shewed
that the chief condition was a swelling of the retro-peritoneal
lymph glands to lumps as large as a fist.

The lymphocytosis following extirpation of the spleen also belongs to
this category, since a vicarious enlargement of the lymph glands is
always to be observed in these cases.

On investigating the conditions under which in healthy individuals an
increased number of lymphocytes enter the blood-stream, we have in the
first place to notice the digestive canal, whose wall contains a thick
layer of lymphatic tissue. According to the results of Rieder the
proportion of the lymphocytes to polynuclears is practically normal in
the leucocytosis of digestion, indeed the lymphocytes are rather in
excess. The eosinophils on the other hand shew a marked relative
reduction in this condition. The leucocytosis of digestion consequently
differs essentially from the other kinds, in which the neutrophil
elements are chiefly increased. The simultaneous increase of lymphocytes
and polynuclears is doubtless brought about by a super-position of a
raised income of lymphocytes, and an ordinary leucocytosis caused by the
assimilated products of metabolism.

The influence of the digestive tract is still more evident in certain
diseases, more particularly in intestinal diseases of infants. A
considerable increase of the lymphocytes in the blood-stream is here t