THE CULTIVATION OF TISSUE IN VITRO 459 



stances upon growth, and Ruth applied it in the investiga- 

 tion of the problems of immunity in cancer. 



Thus a considerable interest in the subject was aroused 

 and it continued to be investigated with enthusiasm, and 

 surprising facts were ascertained, as, for example, that 

 tissues will grow in artificially prepared media Lock's 

 solution and sometimes in heterologous plasma. Also 

 that tissues kept in cold storage may be made to grow 

 if they are sterile as regards bacteria when planted in 

 appropriate media. 



Lambert studied the formation of giant cells in growing 

 tissue, Carrel and Ingebrigsten studied antibody forma- 

 tion in tissue growing outside of the body, and Carrel 

 finally announced that it was possible to keep tissue grow- 

 ing indefinitely outside of the body by proper transplanta- 

 tion and treatment. This led to one of the most interest- 

 ing observations in the whole series, and confirmed the 

 opinion of physiologists that the cardiac muscle contracts 

 through energies intrinsic in it, and not only upon stimula- 

 tion by nervous energy like the voluntary muscles. Frag- 

 ments of heart muscle from an embryo chick were kept 

 growing in vitro. The cells spread out radially forming a 

 thin layer that could be easily observed under the micro- 

 scope. At the end of sixty days they were observed to 

 begin rhythmical pulsation. 



It will be interesting to see whether Carrel's conclusions 

 drawn from his own and Lewis' experiments will ever be 

 justified, but his final conclusion of the whole matter 

 seems to be that it will some day be possible to make use 

 of cold storage for the purpose of keeping alive useful 

 tissues removed by the surgeon, so that they can subse- 

 quently be used for the repair of injured parts and tissues 

 by grafting. 



REFERENCES. 



LEO LOEB: "Ueber die Entstehung von Bindegewebe, Leukocyten, 

 und rothen Blutkorperchen aus Epithel und iiber eine 

 methode isolirte Gewebstheile zu Ziichten," Archiv. f. 

 Entwichelungsmechanik d. Organ., 1902, xiii, 487. 



