24 PRINCIPLES OF GENERAL PHYSIOLOGY 



the adult cat and dog, showing that fragments of various organs, such as 

 kidney, spleen, bone marrow, thyroid, cartilage, etc, placed in coagulated 

 blood plasma, form new cells of the appropriate kind. Rena tubules for 

 example are to be seen increasing in length, and cartilage cells in number, 





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while forming new cartilaginous substance, 

 of a nerve fibre of the chick. 



Fig. 20 represents the growth 



For the details of the method the reader is referred to the articles by Carrel and Burrows 

 (1912), and by Carrel (1912). Further, Carrel (1913) finds that the culture medium is greatly 

 improved by the addition of tissue juice of an adult or embryo animal, the younger the better, 

 but this favourable effect is only shown when the tissue comes from the same species. Pieces 



