452 Mr. A. J. "Walton. Growth of Adult Mammalian 



Jasmin (yellow). — Gave anthocyanimTonly, more readily by means of zinc 

 and 2j$ HC1 than by electrolysis. 



Primrose (yellow). — Easily produced anthocyanin by either method, even 

 in fairly warm HC1 with zinc only anthocyanin was produced. The glucoside 

 produced in this case seemed to be more stable to hydrolysis than in the 

 majority of cases. 



Lemon Peel. — Extract in HC1, in presence of the peel, reduced with zinc 

 gave only anthocyanin. 



Variations in the Growth of Adult Mammalian Tissue in Auto- 

 genous and Homogenous Plasma* 

 By Albert J. Walton, M.S., F.R.C.S., B.Sc. 



(Communicated by Prof. W. Bulloch, F.R.S. Received February 18, — 

 Bead March 26, 1914.) 



(Fi om the Bacteriological Laboratory of the London Hospital.) * 



[Plates 19 and 20.] 



In 1910 Carrel commenced his researches on the growth of tissues outside 

 the body. In 1907 Harrison had succeeded in growing the embryonic tissues 

 of the frog, using coagulable lymph as a medium. In 1910 Harrison and 

 Burrows improved this method and successfully cultivated the tissues of 

 mammalian embryos. Carrel has so modified the technique that the 

 method is now applicable to the study of the growth of all mammalian 

 tissues. He used as a medium the plasma of the animal either in its 

 natural state or modified by the addition of various substances. Since 

 then, he and his collaborators have published a large number of papers, 

 and by their work it has been fully established that tissues of animals, 

 whether embryonic or adult, grow well in vitro ; that by changing the 

 medium and so removing the catabolic substances life can be greatly 

 prolonged — tissues have been kept alive and growing for periods con- 

 siderably longer than a year ; and that the growth of the tissues can be 

 greatly modified by the addition of various substances to, or otherwise 

 altering the composition of, the plasmatic medium. 



* Throughout this paper the term " autogenous " is used to indicate plasma obtained 

 from the same animal as the tissue, " homogenous " to indicate that obtained from 

 another animal of the same species. 



