Plasm

"And that the germ plasm is different from the parthenogenetic egg?" "Why, surely!" I cried, and gloried in my own audacity.

A man very rarely has an image of a person with whom he is livingly, vitally connected. He only has dream-images of the persons who, in some way, oppose his life-flow and his soul's freedom, and so become impressed upon his plasm as objects of resistance.

1990, Robert Wall, This Side Up: Spatial Determination in the Early Development of Animals, Cambridge University Press, 2005, paperback, page 96, The last chapter showed severe limitations in the concept of 'mosaic' development as it applies to spiralian embryos. It did, however, demonstrate differential segregations occurring at cleavage there, and seen for visibly distinct plasms, some macromolecules and determinants inferred from experimental studies.

Shortly after fertilization the cytoplasmic components of the ascidian oocyte are redistributed according to a certain pattern and form five distinct territories or plasms (Figure 4.7). During cleavage these plasms become compartmentalized into different blastomeres which in turn give rise to the various cell lines.