people
On Hamburger's and Holtfreter's scientific biography. Remarks on Holtfreter's "artistic" workstyle.
Handwritten
On his recent vacation.
Handwritten
Handwritten
Handwritten
Detailed description (including several drawings) of Holtfreter's recent observations on Xenopus gastrulae. On induction.
Handwritten
Handwritten
On his difficulties at University of Rochester. On his recent experimental work: "Lately, Hiroko and I have been very busy to unravel the mysteries of the embryo."
Handwritten
On Mascona. On Paul Weiss. On Trinkaus and his own research program: "I cannot see too much sense in the gospel of Trinkaus that it is most important to analyze embryonic determination in terms of cytological rather than histological events. My objection is that the embryo, my teacher, does think in terms of germ layers, even the whole organism and not primarily in terms of individual cells and their subunits." Programmatic letter, mainly on the historical intellectual roots of Holtfreter's research program.