620
I L S E
L A S N I T Z K I
Undifferentiated ducts, on the other hand, follow a neutral development and differentiate into female structures, but contact with testes in
culture or the addition of testosterone propionate to the medium cause
their rapid necrosis. Scheib-Pfieger (1955) found a striking loss of total
nitrogen content in regressing Mullerian ducts treated with testosterone
FIG. 1 1 . Transverse section through a syrinx following male development in vitro. Note
proliferation of cartilage on ventral side. (From Wolff and Wolff, 1953.)
FIG. 12. Transverse section through a duck syrinx which developed according to the female
type in vitro. The cartilage is much thinner than shown in Fig. 1 1 . (From Wolff and Wolff,
1 9 5 3 . )
I L S E
L A S N I T Z K I
Undifferentiated ducts, on the other hand, follow a neutral development and differentiate into female structures, but contact with testes in
culture or the addition of testosterone propionate to the medium cause
their rapid necrosis. Scheib-Pfieger (1955) found a striking loss of total
nitrogen content in regressing Mullerian ducts treated with testosterone
FIG. 1 1 . Transverse section through a syrinx following male development in vitro. Note
proliferation of cartilage on ventral side. (From Wolff and Wolff, 1953.)
FIG. 12. Transverse section through a duck syrinx which developed according to the female
type in vitro. The cartilage is much thinner than shown in Fig. 1 1 . (From Wolff and Wolff,
1 9 5 3 . )