Notochord
Epidermis
Somites
Nervous system
Gut
Blood, Kidney, Heart
FIG. 3. Potentialities of the different fields of the gastrula in culture in vitro. The regions
marked indicate the extent and character ofthe self-differentiating areas in culture in vitro. In
the figure depicting epidermis the points indicate the region from which a typical epidermis
differentiates in experiments on isolated portions of this region. The small circles delimit the
region capable of regulating nito epidermis, neural, chordal and mesodermal tissues. (After
Holtfreter, 1938.)
Epidermis
Somites
Nervous system
Gut
Blood, Kidney, Heart
FIG. 3. Potentialities of the different fields of the gastrula in culture in vitro. The regions
marked indicate the extent and character ofthe self-differentiating areas in culture in vitro. In
the figure depicting epidermis the points indicate the region from which a typical epidermis
differentiates in experiments on isolated portions of this region. The small circles delimit the
region capable of regulating nito epidermis, neural, chordal and mesodermal tissues. (After
Holtfreter, 1938.)