963 
reaction which is positive for myeloblasts whereas it always turns 
out negative for lymphocytes. 
The monistic theory gives more satisfaction for the reason that 
it is more in accordance with the fact that blood and connective 
tissue are by far the most genuine bearers of embryonic characteris- 
ties; it is the tissue from which every thing can originate under 
favourable conditions. This also accounts for the fact that very 
numerous forms of amoeboid cells, the so called wander cells have 
been described, under new names every time, in different parts of 
the body. It is difficult here to give definite characteristics because 
these cells remain rather loose from each other and different kinds 
of cells are found in one anothers immediate proximity. 
For the rest the question should be a settled one for the unpre- 
judiced researcher. Before long already it was found possible 
(amongst others by Maximow by bringing corpora aliena into lymph 
glands) to cause typical myeloid tissue to be formed in atypical 
places. Náeem, who for such cases is dead against the metastasis 
of myeloid tissue from the bone-marrow, could still speak of 
metaplasia here although this appelation does not cover the dualistic 
theory, because after all, it still means that latent characteristics 
under special external influences make their appearance, so that the 
characteristics of the myeloblasts also are a product of external 
influences. Now however that Maximow') a short time back told 
of his success in cultivating myelocytes from lymph gland tissue of 
the rabbit in vitro with the aid of an extract of bone marrow, it 
seems to be high time to relinguish the idea that the myeloblasts 
have specific characteristics, and to accept the broader view that 
the unitarian tenet offers us. This is in accordance with the fact 
that all connective tissue elements are omnipotent up to a certain 
degree and that all these polentialities can be brought to light under 
different external conditions. All these possibilities have as result a 
very great variety of cell forms that can always be found in dif- 
ferent tints and forms of protoplasm and nuclei as for instance, in 
young formative tissue. As long as it has not been possible to show 
why, f.i., the protoplasm of plasma-cells is basophile and why the 
one granulation has more acidic, the other more basic or neutral 
affinities, it is properly speaking not allowed to talk of specific 
characteristics of cells in such cases. Why, f.i., should a lympho- 
cyte which does not give the oxydase reaction and does not exhibit 
typical granulation not bave developed all these characteristics after 
1) C. R. S. d. B.; 69, p. 225 and 235, 1917. 
