Such disturbances he says, acting on the germ-cells, would be truly somatogenic.
"Hormones and Heredity"
J. T. Cunningham
In endeavouring to answer this question there are only two alternatives: either the characters are blastogenic- that is, they arise from some change in the gametocytes occurring somewhere in the succession of cell-divisions of these cells-or they arise in the soma and are impressed on the gametocytes by the influence of the soma within which these gametocytes are contained-that is to say, they are somatogenic.
"Hormones and Heredity"
J. T. Cunningham
For the present, therefore, we must conclude that feathers are not an adaptation, and not due to somatogenic modification, but must be result of a gametogenic mutation.
"Hormones and Heredity"
J. T. Cunningham