devoted a thorough paper containing
many details worthy of note. In the majority of the animals observed, he
found too that the polynuclear cells contained neutrophil granules; in
only one animal, the white mouse, did he find them, or granulations
analogous to them, completely wanting.

According to the investigations carried out some years back in Ehrlich's
laboratory by Dr Franz Mueller, these results of Hirschfeld's must be
described as inaccurate. After many vain endeavours, Dr Mueller was able
to find a method by which numerous though very minute granules could be
found in the polynuclear cells of the mouse. The case shews that it is
not permissible to assume the absence of granules, when the ordinary
staining methods are not at once successful. There is no universal
method for the staining of granules, any more than for the staining of
various kinds of bacteria. Indeed all granules, that are easily soluble,
vanish when the triacid method is used, and so a homogeneous cell
protoplasm is simulated.

But naturally, the occurrence of non-granulated polynuclear cells in
certain classes of animals is not to be denied from these
considerations. Hirschfeld asserts that such cells occur side by side
with granulated cells, for instance in the dog; and draws from them
far-reaching conclusions as to the meaning of the granules. From
Kurloff's work (see p. 85) we must insist, on the contrary, that there
is no evidence that the non-granulated polynuclears are identical with
the granulated cells. Kurloff has shewn, at least for guinea-pig's
blood, that these two heterogeneous elements are to be sharply separated
one from the other, and that they have an entirely different origin.

Specially important for a theory of the nature of the granules is the
circumstance, that generally speaking in all species of animals =they are
present in those cells of the blood only which are adapted to and
capable of emigration=. That a certain nutritive function is to be
ascribed to the emigration of the granulated cells is a very obvious
supposition, scarcely to be denied; and naturally cells with a plentiful
store of reserve material are eminently suited for this purpose. The
lymphocytes on the contrary, incapable of emigration, are almost totally
devoid of specific granulations.

A further indication that =the granulations really are connected with a
specific cell activity lies in the fact, that one cell bears but one
specific granulation=.