662
H O N O R
B . F E L L
A N D L . M .
R I N A L D I N I
immediately suppresses ciliation, gradually inhibits the development
of mucous cells and glands and produces a thick, stratified epithelium.
These encouraging results suggest that it may now be possible to
study some of the metabolic effects that accompany the morphological
changes characteristic of vitamin A-deficiency.
FIG. 3. Tracheal epithelium from a 13-day chick embryo after 6 days' cultivation in normal
medium. The epithelium is well ciliated, and mucous cells are beginning to form small,
intra-epithelial glands. X625. (Aydelotte, 1963a.)
FIG. 4. Tracheal epithelium from a 13-day chick embryo after 6 days' cultivation in a medium
containing 2*0 m M citral. At the edge of the explant the basal cells have multiplied and
differentiated into a stratified, squamous epithelium; the superficial mucous cells are
vacuolated and being sloughed. x625. (Aydelotte, 1963a.)
H O N O R
B . F E L L
A N D L . M .
R I N A L D I N I
immediately suppresses ciliation, gradually inhibits the development
of mucous cells and glands and produces a thick, stratified epithelium.
These encouraging results suggest that it may now be possible to
study some of the metabolic effects that accompany the morphological
changes characteristic of vitamin A-deficiency.
FIG. 3. Tracheal epithelium from a 13-day chick embryo after 6 days' cultivation in normal
medium. The epithelium is well ciliated, and mucous cells are beginning to form small,
intra-epithelial glands. X625. (Aydelotte, 1963a.)
FIG. 4. Tracheal epithelium from a 13-day chick embryo after 6 days' cultivation in a medium
containing 2*0 m M citral. At the edge of the explant the basal cells have multiplied and
differentiated into a stratified, squamous epithelium; the superficial mucous cells are
vacuolated and being sloughed. x625. (Aydelotte, 1963a.)