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Scientific Proceedings (44). 
and rat tumors. Liquefaction about the pieces of tissue is often 
quite marked. With sarcoma the growth, though relatively slow, 
may continue for ten to twelve days. 
In dog plasma pieces of sarcoma, after one or two days, present 
a fairly diffuse radial outgrowth of clear spindle cells, which after 
this time undergo rapid disintegration. About the pieces there is 
noted a narrow clear zone (liquefaction) . With mouse carcinoma 
liquefaction is more marked and there is little or no outwandering 
of cells. 
We have not observed any of the phenomena of growth when 
using goat plasma. After a few hours there is seen surrounding 
the pieces of tissue a wide granular zone. Liquefaction of fibrin 
does not occur. 
In human plasma the most striking and constant phenomenon 
is the progressive liquefaction of the fibrin, which is practically 
complete after six or seven days. In spite of the loss of framework 
there takes place, however, an active migration of cells, which 
wander out along the cover glass, reaching often the edge of the 
medium. As a rule the cells move out separately, but we have 
observed in several preparations of rat spleen radial out-growths 
simulating the appearance seen in homologous plasma where the 
fibrin network is preserved. In the single cells attached to the 
cover glass the most interesting changes have been noted, especially 
in the cultivation of rat spleen. After four or five days cells of 
extraordinary size begin to appear, reaching a maximum size in 
two or three days. Such a " giant cell" examined in the fresh 
state shows about its centre a clear nuclear area, with or without 
knob-like prominences, surrounded by a highly granular zone, 
which in turn merges into a clear filmy indefinite protoplasm with 
processes. In their entire extent these cells vary from 100 to 700 
mikra in diameter. When stained the knob-like prominences are 
seen to be nuclei with distinct nuclear membranes and prominent 
nucleoli. These nuclei are often seen in close apposition arranged 
about a light hematoxylin staining, reticular or vacuolated area. 
In the fresh this portion of the cell was interpreted as nucleus. 
Many large cells varying considerably from these were also seen. 
Quite large multinucleated cells have been observed in the growth 
of sarcoma and carcinoma in rat plasma but none that simulated 
