Sporozoa in Sarcoma. 
811 
parasites in the intestine of the cockroach and elsewhere, and the 
same pkysical properties, density and high power of refraction, are 
eDCOuntered in the undoubted psorosperms as I have described them 
in the urinary tract of man. Although in themselves indistinguish- 
able from colloid drops they assume a greater importance when seen 
side by side with cell-inclusions which possess the same properties 
and in addition are provided with a definite, though often peculiar, 
nucleus, such as the larger of the bodies within the cell shown in 
fig. 2. This body affords evidence of having given rise to similar 
smaller bodies some of which have nuclei and others are non- 
nucleated. In such nucleated cell-inclusions I have observed amoeboid 
movements. In many cancer-cells groups of small encapsuled cell- 
inclusions occur such as are shown in fig. 3. Again in other cells 
of cancers the large dense bodies may be observed to have sub- 
divided into smaller fragments and to present the appearance of 
budding off daughter cells at the periphery. Some of the daughter- 
cells may be observed free in the connective-tissue of the growth 
where they are readily distinguishable by their staining-reactions and 
their form, see fig. 4. There it would be well to describe a little 
in detail the staining reactions of these bodies. With Biondi they 
are usually of a reddish tint and with haematoxylin and eosine of a 
beautiful magenta colour, still they are not altogether refractory to 
nuclear dyes and they may be green when stained with Biondi 
and dusky-purple when stained with haematoxylin alone. Their nuclei 
when present stain sometimes differently from the nuclei of tissue 
cells, to this phenomenon Soudakewitch has applied the term 
“metachromatism”. The parasites described byVan der Loeff, 
L. Pfeiffer 1 2 ), and Guarnieri, in vaccinia and variola whose 
conclusions I have been able to confirm, have quite similar staining 
reactions &c to these bodies which are of constant occurrence in 
cancer. 
Turning now to sarcoma I will illustrate my views by elements 
which are present in great numbers in many such growths. Figs. 5 
—11 are taken from sections of a periosteal sarcoma of the femur 
removed by Mr. E. Owen at St. Mary’s Hospital and fig. 12 from 
the round-celled sarcoma of the testis already referred to. Fig. 5 
shows a cell containing a large nucleated and two smaller non- 
nucleated parasites. Stained with haematoxylin and eosine the small 
dense nucleus of the larger parasite was of a purple colour and the 
body of the parasite was rose-red. The cell in fig. 6 contains three 
parasites and is exactly comparable to that shown in fig. 3 from 
the cancer of the breast. Fig. 7 shows a capsule with the adherent 
nucleus of the host-cell and several dense bodies which may, I think, 
be justly compared to the conditions shown in figs. 2 and 4. Many 
of the parasites show signs of irregulär mitotic activity like that 
represented in fig. 8. Others again present a large homogeneous 
nuclear body which gives a metachromatic nuclear reaction and around 
1) L. Pfeiffer, „Behandlung und Prophylaxe der Blattern“ (Jena 1893) gives 
the literature relating to this subject. 
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