two componenta and shows great variations from animal to animal
(Table II).
The present renulta are oompatible with the notion that
the larger psrt of the oytopleamio RNA derives from the moleolus,
sinoe differenoee in base compoeition are found only
in late growth etagee when the nuoleolus is about to disappear.
The oause of the ohange in nuoleolar BNA oompoeition is unknown
and my be the result either of ohanged proportions
between different BNA fraotions, known to exist here (Vinoent,
1954; Sibatani et al. 19621 Adams and Busoh, lY62), or of