authors' abstract of this paper is- 

 sued BY THE BIBLIOGRAPHIC SERVICE. 



BEHAVIOR OF CROSS STRIATED MUSCLE IN 

 TISSUE CULTURES 



WARREN H. LEWIS AND MARGARET R. LEWIS 



FroDi Jdfuix Hopkins University and Department of Embryology, 

 Carnegie Institution of Washington 



FOURTEEN FIGURES 



Abundant outgrowth of skeletal muscles of chick embryos 

 can readily be obtained by means of tissue cultures in Locke's 

 solution, with or without the addition of other substances. 

 The characteristic outgrowth can be recognized at a glance 

 and presents features of unusual interest. That such a highly 

 differentiated tissue as cross-striated muscle should grow out 

 so abundantly in Locke's solution is somewhat surprising. 



Harrison '10 noticed in cultures of tadpole tissues in frog 

 lymph in a few instances, where the explanted myotome was 

 thin, that the primitive myoblasts differentiated into cross- 

 striated fibers. He did not find, however, that the myoblasts 

 grew out into the culture medium. That amphibian embryonic 

 tissue, where the amount of stored egg yolk supply is consid- 

 erable should retain the power of differentiation outside the body 

 agrees in general with what we know in regard to the power of 

 self-differentiation exhibited by such tissues when they are 

 transplanted to other parts of the same or different embryos. 

 It indicates that muscle, or better, premuscle tissue can proceed 

 along the path or at least a certain portion of its path of differ- 

 entiation independently of any specific influences from the other 

 tissues of the embryo. The possibilities of such self -differen- 

 tiation are already inherent in the cells that are destined to 

 form muscle in the wide open blastopore stage of the frog. 

 For, as pointed out by Lewis, pieces of the rim of the blastopore 

 when transplanted into older embryos continue to differentiate 

 into muscle, notochord and nervous system. 



169 . 



THE AMERICAN JOURNAL OF ANATOMY, VOL. 22, NO. 2 

 SEPTEMBER, 1917 



