Plastosome

The plastosome itself sometimes survives the growth period as a unit, though often it does not.

Just as a nucleus has always for its genesis a division of a mother-nucleus, so have the plastosomes for their origin a division of a mother-plastosome.

These granules later (early spermatocytes) disappear from the nucleus simultaneously with the disappearance of the plastosome.

The shape of the plastonema and its relation to the plastosome appear clearly in figures 1, 2, and 3.

The proplastid of I. howellii is a flattened structure that is differentiated into a plastonema and a plastosome. Lamellae and starch granules appear first in the plastonema and later in the plastosome.