An Addition to the Technique of the Cultivation of Tissues in Vitro

We have employed two kinds of media; namely, natural and artificial, so called. The natural media were solid or fluid, consisting either of coagulated plasma or fluid serum. Coagulated plasma has always given the best cultural results. The plasma can be kept in a fluid condition in cold storage for a long time. We have found chicken plasma, after having been preserved for two months, to be still an excellent culture medium. The use of the plasmatic medium is, therefore, very convenient. Autogenic and homogenic plasma constitute the best media, but heterogenic plasma can also be used, as has been shown by Lambert and Hanes3 For instance, in our experiments fetal tissues of the chicken grew extensively in human, rabbit, and dog plasma. In general, however, it may be said that the development of the tissues