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J E A N B R Ä C H E T
FIG. 18. Control Hydra: posterior segment 3 days after sectioning; regeneration of
tentacles and budding : the right bud has just fallen off the left Hydra.
Once more, t h e inhibition of b l a s t e m a formation is p r e s u m a b l y d u e t o
inability of t h e cells t o migrate, r a t h e r t h a n t o a block in m i t o t i c
a c t i v i t y (Figs. 16, 17).
H e r e too, dithiodiglycol is m o r e toxic t h a n m e r c a p t o e t h a n o l ; it m u s t
be used a t concentrations of t h e order of M/3,000 t o M/10,000. U n d e r
these conditions, regeneration proceeds normally, except t h a t t h e
p i g m e n t a t i o n of t h e regenerated h e a d is definitely delayed, if n o t
completely inhibited.
Finally, m e r c a p t o e t h a n o l inhibits regeneration in h y d r a , while
dithiodiglycol is inactive or toxic, depending on t h e c o n c e n t r a t i o n
(Descotils-HeernueiaZ., 1961) (Figs. 18, 19).
J E A N B R Ä C H E T
FIG. 18. Control Hydra: posterior segment 3 days after sectioning; regeneration of
tentacles and budding : the right bud has just fallen off the left Hydra.
Once more, t h e inhibition of b l a s t e m a formation is p r e s u m a b l y d u e t o
inability of t h e cells t o migrate, r a t h e r t h a n t o a block in m i t o t i c
a c t i v i t y (Figs. 16, 17).
H e r e too, dithiodiglycol is m o r e toxic t h a n m e r c a p t o e t h a n o l ; it m u s t
be used a t concentrations of t h e order of M/3,000 t o M/10,000. U n d e r
these conditions, regeneration proceeds normally, except t h a t t h e
p i g m e n t a t i o n of t h e regenerated h e a d is definitely delayed, if n o t
completely inhibited.
Finally, m e r c a p t o e t h a n o l inhibits regeneration in h y d r a , while
dithiodiglycol is inactive or toxic, depending on t h e c o n c e n t r a t i o n
(Descotils-HeernueiaZ., 1961) (Figs. 18, 19).