rodin,
phenacetin call forth even in man a considerable increase of the
leucocytes besides the destruction of the red blood corpuscles. This has
been observed experimentally by Rieder.

We observed marked increase of the white blood corpuscles after
poisoning from arsenurietted hydrogen, from potassium chlorate, further
in a fatally ending case of haemoglobinuria (sulphonal poisoning?) as
well as after protracted chloroform narcosis.

3. The =leucocytosis= which accompanies acute and chronic anaemic
conditions, especially posthaemorrhagic.

4. =Cachectic leucocytosis= in malignant tumours, phthisis, etc.[26]

To enter here more precisely into the special clinical importance of
blood investigation in different forms of disease would lead us too far,
and we refer for this subject to the excellent and thorough monograph on
leucocytosis by Rieder and to the papers of Zappert and Tuerk. In this
place we will only touch on the most weighty points.

[alpha]. The importance for differential diagnosis of the leukopenic
blood condition in typhoid fever as compared with other infectious
diseases, and in measles as against scarlet fever.

[beta]. The prognostic importance of the enumeration of the white
blood corpuscles. Thus for example the absence of leucocytosis
influences the prognosis of pneumonia unfavourably (Kikodse and others);
and the appearance of numerous myelocytes in diphtheria is ominous, as
demonstrated by C. S. Engel (see page 78).

* * * * *

Finally, we may dismiss in a few words the origin of ~polynuclear
neutrophil leucocytosis~, and refer to what has been said in another
place on the function of the bone-marrow.

In agreement with Kurloff's researches, Ehrlich formulated ("On severe
anaemic conditions" 1892) his views on this subject as follows: "The
bone-marrow is a breeding place in which polynuclear cells are produced
in large numbers from mononuclear pre-existing forms. These polynuclear
cells possess above all other elements the power of emigration. So soon
as chemiotactic substances circulate in the blood, which attract the
white elements, this power comes into play. This readily explains the
rapid and sudden appearance of large numbers of leucocytes, which so
many substances bring about, and particularly the bacterio-proteins,
recognised by Buchner as leucocytic stimuli. I regard leucocytosis
therefore, in agreement with Kurloff, as a function of the bone-marrow.