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A TEXTBOOK OF PHYSIOLOGY 



lymph sac of the same animal showed active cilia after five months 

 Pieces of human skin kept in ascitic fluid for at least one week have 

 grown on transplantation. The cornea of a hare kept at C. has 

 survived nine to twelve days, and been successfully transplanted. 

 The excised heart of a three-months-old child has been made to beat 

 twenty hours after death. In the last few years the survival of tissue 



FIG. 11. CAMERA LUCIDA DRAWING OF CELLS FROM THE HEART OF RABBIT'S 

 EMBRYO (.SEVEN TO EIGHT DAYS OLD) GROWING IN CULTURE MEDIUM. (N. C. 

 Lake, from Journal of Physiology.) 



A, Main mass of tissue; B, degenerate cells; C, inner columnar cell; D, liquefied 

 medium; E, protoplasmic thread; F, outer spindle cell; G, fibrin network with 

 blocd platelets at nodes; H, nucleus showing chromatin; /, tendency to striation. 



cells has been extensively studied, and the question arises as to whether 

 true cultures are obtained. The growth of nerve cells has been studied 

 in pieces of the frog embryo placed in clotted frog's lymph. By 

 repeatedly alternating the life of the tissue, first putting it in a culture 

 medium and warmth and then in Ringer's solution and cold, pulsating 

 pieces of heart muscle have been kept for three months. Cell move- 



