98
BRIAN POOLE
Growth of the tissue occurs only when there are free templates, that
is, only when the antitemplate concentration is below a certain level. This
occurs only when the tissue mass is below a certain size. Thus the process
FIG. 2. Diagrammatic representation of Weiss-Kavanau theory of tissue specific
growth control. The large rectangles around the two diagrams represent the boundary of the organism. The small solid triangles and circles represent inhibitors of the
growth of the triangular and circular tissue masses, respectively. The two tissue
masses (large triangle and circle) are shown surrounded by the fluids bathing the
tissues (the space between the boundaries of the tissue masses and the boundary
of the organism). The small double circles and triangles within the tissue mass
represent the tissue-specific inhibitor-binding sites. The arrows crossing the boundaries of the tissue masses represent inhibitor production by the tissues, and the
arrows crossing the boundary of the organism represent inhibitor excretion or
degradation.
In diagram A the growth of both the triangular and the circular tissue masses is
slow, one-sixth of capacity (five-sixths of the binding sites are saturated). In
diagram Β we have reduced the mass of circular tissue by one-half. The inhibitor
production is reduced by one-half, and the inhibitor concentration in the body
fluids drops to a lower level. More binding sites in the circular tissue are freed,
and the growth rate increases to two-thirds of capacity (only one-third of the binding sites are saturated now). The operation has no effect on the inhibitor balance
or growth rate of the triangular tissue mass.
of growth cannot occur beyond a certain point because the increased tissue
mass produces an increased inhibitor concentration. To explain the process
of normal growth of a whole organism it is necessary to introduce the
additional assumption that the ratio of the free diffusion volume of the
BRIAN POOLE
Growth of the tissue occurs only when there are free templates, that
is, only when the antitemplate concentration is below a certain level. This
occurs only when the tissue mass is below a certain size. Thus the process
FIG. 2. Diagrammatic representation of Weiss-Kavanau theory of tissue specific
growth control. The large rectangles around the two diagrams represent the boundary of the organism. The small solid triangles and circles represent inhibitors of the
growth of the triangular and circular tissue masses, respectively. The two tissue
masses (large triangle and circle) are shown surrounded by the fluids bathing the
tissues (the space between the boundaries of the tissue masses and the boundary
of the organism). The small double circles and triangles within the tissue mass
represent the tissue-specific inhibitor-binding sites. The arrows crossing the boundaries of the tissue masses represent inhibitor production by the tissues, and the
arrows crossing the boundary of the organism represent inhibitor excretion or
degradation.
In diagram A the growth of both the triangular and the circular tissue masses is
slow, one-sixth of capacity (five-sixths of the binding sites are saturated). In
diagram Β we have reduced the mass of circular tissue by one-half. The inhibitor
production is reduced by one-half, and the inhibitor concentration in the body
fluids drops to a lower level. More binding sites in the circular tissue are freed,
and the growth rate increases to two-thirds of capacity (only one-third of the binding sites are saturated now). The operation has no effect on the inhibitor balance
or growth rate of the triangular tissue mass.
of growth cannot occur beyond a certain point because the increased tissue
mass produces an increased inhibitor concentration. To explain the process
of normal growth of a whole organism it is necessary to introduce the
additional assumption that the ratio of the free diffusion volume of the