Show I 1 ABLE experiments dr alexis carrels wonderful progress in research lever physician of rockefeller institute tells of keeping cells alive two and a half years out of the body new york dr alexis carrel of 0 the rockefeller institute has from time lima to time told of the progress of tits his experiments in keeping living tissue alive in glass jars ile he describes some connective tissue derived on january 17 1912 from the heart of a chicken embryo seven dayo daya old this is still living and growing though it Is now two years and a halt since it was taken from the chick the fragments of heart pulsated for days daya and gave rise to a very largo large number of connective tissue cells wrote doctor carrel this means that it not only lived but grew these cells multiplied actively during the last two years continued carrel and proa produced a large amount of connective tissue at present a great many cultures are obtained from the strain every week doctor carrel measures the growth of a piece of this tissue by removing a fragment from a culture washing it in ringer solution placing it in a new medium and after 48 hours measuring the ring of new tissue that has formed around it the fragments of tissue he says usually double in 48 hours the rate of growth varies with the medium but under favorable circumstances the ring of new tissue has grown from one twelfth to one tenth of an inch in 48 hours an extraordinary fact noted by doctor carrel is that the amount of new tissue produced by a given culture ot of this same strain today is almost double the amount produced a year ago in other words this tissue is stronger than it was originally doctor carrel compared the rate of growth of this two and a halt half year old tissue with that of fresh tissue from the heart of a chick embryo eight days lea J N az 7 z f I 1 r W W e fragment ent of connective tissue taken after 28 months from a culture taken from the heart ot of an embryo chicken on january 17 1912 above one hour after being placed in fresh medium be below 0 o w 45 hours later showing ing the growth of the tissue I 1 in n that time enormously magni masal ned fled the width of the ring of new tissue in the lower picture Is in reality about one tenth of an inch old and found after 48 hours that the tissue which had become adapted to life in vitro had increased much more rapidly than the fresh tissue it if nis e exclude accidents concludes doctor carrel connective tissue cells like ilke colonies of may pr ata at indefinitely this is by far the tha most remarkable contribution to the problem of life outside the body that has yet been made demonstrating that some at any rate of the cells that make up the bodies of animals have in themselves a power not only of independent life but of drawing from a suitable medium the material necessary to growth growt h and thus of reproducing themselves tor for a seemingly indefinite time |