it is almost constantly associated Avith the preceding,
is very regularly spindle-shaped ; and a third, Avhich
may possibly present generic differences, has the form
of a truncated cylinder. In this last Ave have
observed the process of endogenous multiplication
../ii
F ig . 22.— Pijronstis fusiformis, M u rra i-. From th e surface in th e Guinea Current.
One Imndred times tlie n a tu ra l size.
by the division of the protoplasmic nucleus and the
development of two secondary cells within the
parent. We are at present inclined, though Avith
some doubt, to relegate these forms to the Diatom
acese.
