THE ADDITION OF DETAILS 8 1 



very enthusiastic Russian embryologist, who was full 

 of the similarity between the organization centre and 

 the Communist party. He said that the organizer 

 arises as a small ordered part of the egg, and when 

 a revolution happens (that is, gastrulation occurs) 

 the organizer remains in control because of its own 

 order and discipline, just like the Communist party 

 in Russia, according to him. As soon as the main 

 job is over the party starts a lot of separate factories 

 going, each to perform some special function, and 

 these factories are quite self-sufficient within their 

 own limits and elect their own executives, just as the 

 secondary organizers and the regions controlled by 

 them can self-differentiate and act as harmonious 

 equipotential systems, running their own show with- 

 out much control from the primary organization 

 centre. I do not know enough about Russia to say 

 whether the Communist party really works like that, 

 but the comparison does bring out some important 

 features of the way the organizers work. 



Once an organ rudiment has been determined 

 and starts self-differentiating, it is amazing how 

 fully and in what detail it develops. A very good 

 example of this is seen if the rudiment of the leg- 

 bones are removed from a chicken embryo and grown 

 in a culture, like the cultures used for growing entire 

 embryos. Miss Fell, collaborating with Dr. Canti, 

 has made a cinematograph film of what happens, 

 and the pictures shown in Fig. 22 are taken from this 

 film. When the rudiment was isolated from the 

 embryo, it was a little shapeless mass of mesoderm. 



