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Scientific Proceedings (44). 
tissue, the regenerating cells of the tubules pushing the older cells 
into the lumen of the tubule and such desquamated necrotic cells 
glue together and form casts. Tubular epithelium can also grow 
between the transplanted piece of kindey and the coagulum and 
sometimes it penetrates into the coagulum forming occasionally 
canals in the latter. Mitoses are seen in the proliferating cells 
of parenchyma and stroma and such cells dividing mitotically 
may be seen lying directly in the coagulum. This description 
holds good for the ordinary manner of experimentation. Under 
certain conditions which we expect soon to describe in more detail 
it seems possible to increase very markedly the proliferating and 
infiltrating activity of the tubules. 
4. In the case of the mammary carcinoma of the mouse the 
growth of the parencyhma is very much more prominent than in 
the case of the normal organs examined, a fact that is in accordance 
with the rapid growth of carcinoma cells in contact with animal 
cells in the body. 
5. While various authors state that after the ordinary trans- 
plantation of carcinoma of the mouse into the subcutaneous tissue 
the stroma perishes and only the parenchyma remains alive, after 
transplantation into the culture media the stroma of mouse car- 
cinoma remains alive and shows even certain growth phenomena. 
This observation should suggest a renewed investigation of the 
fate of the stroma after transplantation of carcinoma into the sub- 
cutaneous tissue of an animal. 
6. Both parenchyma and stroma of the carcinoma of the mouse 
grow approximately equally well in coagulated blood plasma of the 
rat and of the rabbit. 
7. The parenchyma cells of carcinoma penetrate very much 
more frequently into the coagulum than the parenchyma cells of 
other organs investigated so far. Mitoses are frequently seen 
in the carcinomatous cells and they may even be found in cells 
lying in the coagulum. 
8. In regard to the skin we observed in our early experiments 
published elsewhwere the epithelial cells to penetrate in relatively 
large masses into the coagulum and we furthermore described 
at that time mitoses in these infiltrating epithelial cells. 
C. We also noticed that the epithelial cells of the skin may 
