232
S I L V I O R A N Z I
ions are arranged in order of their activity, it appears that they are also
arranged according to the lyotropic series of Hofmeister, f The greater
the activity in inducing cyclopia (or vegetaUzation), the greater the
activity in precipitating colloids; on the other hand, ions with more
swelling activity are more active in inducing notochord enlargement (or
animalization) (Ranzi, 1943). Substances interacting with carbohydrate
metabolism (DL-glyceraldehyde, NaF, monoiodoacetate) do not induce
vegetalization or notochord reduction, so that the changes in the determination are not related to a specific disturbance of carbohydrate
oil
fc
clear
/
layer—·./
mitochondria ^l.·.·.
Yolk-Ηί
pigment-—*
N
M
fConrrol
51
0.628
ILiCl
51
0.668
fConhrol
50
0.690
LNaSCN
50
0.616
FIG. 21. Arbacia lixula centrifuged egg. M: b/a; N : number of eggs measured (from
Abruzzese Sgarlata, 1947).
metabolism (Tamini, 1943a, b). These data suggest that substances
changing embryonic determination act directly on embryonic protoplasmic ultra-structure.
To investigate this directly, Abruzzese Sgarlata (1947) treated unfertilized eggs of Arbacia with NaSCN or LiCl and then centrifuged
them. In NaSCN-treated eggs stratification occurred more quickly, and
in LiCl-treated eggs it occurred more slowly than in the controls (Fig.
21). This work was confirmed and extended to fertilized eggs by Lallier
(1955).
In order to study the differences between normal, vegetalized and
f In their ability to induce amphibian cyclopia, Tamini (1943a, b) gave the following
series: LiCl>Na 2 S0 4 >NaCl>MgCl 2 >Na-tartrate, with ethanol least active. The corresponding series inducing sea urchin vegetalization is LiCl>MgS0 4 >MgCl 2 >Na 2 S0 4 >
Na-tartrate>ethanol. Ranzi (1943) studying the development of the notochord in the
frog found the series S 0 4 — > Cl~ > t a r t r a t e — > I - > S C N ~ for Na salts, where S0 4 —
corresponds to the maximum notochord inhibition and SCN~ to the maximum increase
in notochord size.
: 0.077
r = 2.04
P < 0.05
r = 2.37
P < 0.05
S I L V I O R A N Z I
ions are arranged in order of their activity, it appears that they are also
arranged according to the lyotropic series of Hofmeister, f The greater
the activity in inducing cyclopia (or vegetaUzation), the greater the
activity in precipitating colloids; on the other hand, ions with more
swelling activity are more active in inducing notochord enlargement (or
animalization) (Ranzi, 1943). Substances interacting with carbohydrate
metabolism (DL-glyceraldehyde, NaF, monoiodoacetate) do not induce
vegetalization or notochord reduction, so that the changes in the determination are not related to a specific disturbance of carbohydrate
oil
fc
clear
/
layer—·./
mitochondria ^l.·.·.
Yolk-Ηί
pigment-—*
N
M
fConrrol
51
0.628
ILiCl
51
0.668
fConhrol
50
0.690
LNaSCN
50
0.616
FIG. 21. Arbacia lixula centrifuged egg. M: b/a; N : number of eggs measured (from
Abruzzese Sgarlata, 1947).
metabolism (Tamini, 1943a, b). These data suggest that substances
changing embryonic determination act directly on embryonic protoplasmic ultra-structure.
To investigate this directly, Abruzzese Sgarlata (1947) treated unfertilized eggs of Arbacia with NaSCN or LiCl and then centrifuged
them. In NaSCN-treated eggs stratification occurred more quickly, and
in LiCl-treated eggs it occurred more slowly than in the controls (Fig.
21). This work was confirmed and extended to fertilized eggs by Lallier
(1955).
In order to study the differences between normal, vegetalized and
f In their ability to induce amphibian cyclopia, Tamini (1943a, b) gave the following
series: LiCl>Na 2 S0 4 >NaCl>MgCl 2 >Na-tartrate, with ethanol least active. The corresponding series inducing sea urchin vegetalization is LiCl>MgS0 4 >MgCl 2 >Na 2 S0 4 >
Na-tartrate>ethanol. Ranzi (1943) studying the development of the notochord in the
frog found the series S 0 4 — > Cl~ > t a r t r a t e — > I - > S C N ~ for Na salts, where S0 4 —
corresponds to the maximum notochord inhibition and SCN~ to the maximum increase
in notochord size.
: 0.077
r = 2.04
P < 0.05
r = 2.37
P < 0.05