Correspondence
On his second review of the regulatin of the organizer action. On archencephalic differentiation. On his review of the genetic control of convergent extension (stretching).
Letter about visit
Short note on NGF findings.
On finishing the last chapter of their book manuscript. Mainly private letter, sending Season's greetings and x-mas gifts.
On his upcoming visit to St. Louis.
request for reprints, discussion of rhythmical behavior in the chick embryo and many questions posed on the subject
On his birthday and christmas. On Hamburger's upcoming visit to Boston.
Letter accompanying two diagrams by Yip on cell degeneration.