MORPHOGENESIS IN STENTOH
9
any external interference (Tartar, 1960a) as, for example, when a concentrated sample is placed in a caster dish and denied further nutriment. After about two weeks unusually long and narrow forms appear
which later become tadpole-shaped; eventually all normal form is lost
as finger-like processes develop in any direction (Fig. 5). The macroFIG. 5. Amorphogenesis. Normal animals (first sketch) placed in dish without further
nutrition develop elongated forms with central core of pigment granules, modifying to
tadpole-shaped animals and eventually becoming amorphous with random projections.
nuclear nodes remain normal in appearance but invariably there is an
unusual accumulation of pigment granules in the interior as a central
core, the surface becoming progressively colourless. Presumably the
surface pattern becomes completely disorganized, although this is difficult to determine because of the loss of pigment stripes. This change is
not the normal response to starvation, for then the cell simply becomes
more and more pellucid and dies while retaining the normal form. One
is tempted to call the abnormal forms 'cancerous' because the normal
control of the integration of parts seems to be entirely lost. A possible
interpretation is that if the cortical granules (pigmented in coeruleus but
present in all species) for some reason move from the surface into the
interior, a proper spacing of the ciliary rows usually separated by these
granular bands no longer obtains and they interact abnormally with each
other through close juxtaposition.
IV. Relation of Cell Elaborations to the Cortical Pattern
A. Induction of Membranellar Bands
Pigment bands are graded in width from wide to narrow around the
cell. This is because the widest stripes produce the fine stripes by a
splitting which is either caused by or allows interpolation of new unpigmented stripes of cilia and contractile fibres. Narrow pigmented bands
then gradually increase in width as new ones are added. The result is
9
any external interference (Tartar, 1960a) as, for example, when a concentrated sample is placed in a caster dish and denied further nutriment. After about two weeks unusually long and narrow forms appear
which later become tadpole-shaped; eventually all normal form is lost
as finger-like processes develop in any direction (Fig. 5). The macroFIG. 5. Amorphogenesis. Normal animals (first sketch) placed in dish without further
nutrition develop elongated forms with central core of pigment granules, modifying to
tadpole-shaped animals and eventually becoming amorphous with random projections.
nuclear nodes remain normal in appearance but invariably there is an
unusual accumulation of pigment granules in the interior as a central
core, the surface becoming progressively colourless. Presumably the
surface pattern becomes completely disorganized, although this is difficult to determine because of the loss of pigment stripes. This change is
not the normal response to starvation, for then the cell simply becomes
more and more pellucid and dies while retaining the normal form. One
is tempted to call the abnormal forms 'cancerous' because the normal
control of the integration of parts seems to be entirely lost. A possible
interpretation is that if the cortical granules (pigmented in coeruleus but
present in all species) for some reason move from the surface into the
interior, a proper spacing of the ciliary rows usually separated by these
granular bands no longer obtains and they interact abnormally with each
other through close juxtaposition.
IV. Relation of Cell Elaborations to the Cortical Pattern
A. Induction of Membranellar Bands
Pigment bands are graded in width from wide to narrow around the
cell. This is because the widest stripes produce the fine stripes by a
splitting which is either caused by or allows interpolation of new unpigmented stripes of cilia and contractile fibres. Narrow pigmented bands
then gradually increase in width as new ones are added. The result is