Cultivation of Tissue in Plasma from Alien Species. 123 
periods, and by the 25th day following, the entire culture had died 
out. In another culture, which was started from this one at the 
150th generation and kept on a hay infusion medium, conjugation 
did not occur and this culture is still alive. 
75 (600) 
The cultivation of tissue in plasma from alien species. 
By ROBERT A. LAMBERT and FREDERIC M. HANES. 
[From the Department of Pathology of the College of Physicians 
and Surgeons, Columbia University.] 
The present series of experiments have been concerned with 
the attempt at cultivating in vitro rat sarcoma, rat spleen and 
mouse carcinoma, in plasma obtained from animals of other species, 
and at analyzing the factors contributing to the phenomena ob- 
served. 
In a former note we recorded the fact that mouse and rat 
plasma could be interchanged as culture media for the tumors of 
these species, but that growth seemed to be more vigorous when 
homologous plasma was used. Guinea pig, rabbit, dog, goat, 
human and pigeon plasmas have been employed in the studies 
herewith reported. 
For determining the viability of tissue under the conditions 
of the experiment we have made transfers of the pieces to homolo- 
gous plasma — a rapid and satisfactory test. Animal inoculations 
have also been made in the case of tumor tissue, but aside from 
the delay in noting the results the procedure has other objections. 
As a culture medium for rat sarcoma guinea pig plasma is only 
slightly less suitable than rat plasma, the difference consisting 
chiefly in the extent of the out-wandering of cells. The cells may 
remain viable in a single drop of plasma for twelve days or more ; 
we have had pieces which showed marked activity after a month's 
sojourn in several drops of the alien medium. Mouse carcinoma 
seems to grow almost as well in guinea pig plasma as in rat plasma. 
Mitoses have been observed after eight days, and cultures nine 
days old produced tumors when inoculated into mice. 
Rabbit plasma is distinctly less suitable for the growth of mouse 
