Microenvironmental Influences in Cytodifferentiation 241 



sociated cells, in Developing: Cell Systems and Their Control, ed. by D. Rud- 

 nick. The Ronald Press Company. New York. 



Niu. M. C. (1956), New approaches to the problem of embryonic induction, in 

 Cellular Mechanisms in Differentiation and Growth, ed. by D. Rudnick. Prince- 

 ton University Press. Princeton, N.J. 



Weiss. P. (1933), Functional adaptation and the role of ground substances in devel- 

 opment, Am. Naturalist. 67:322-340. 



(1958). Cell contact. Intern. Rev. Cytol., 7:391-423. 



Wilde, C. E. (1960), Factors concerning the degree of cellular differentiation in 

 organotypic and disaggregated tissue cultures, Colloq. intern, sur la Cult. 

 Or gano-ty pique (in press). 



