Note 60 — THE INDIVIDUAL ORGANISM WITH REGARD TO FORM AND METABOLISM (continued 2)

This statement is not strictly correct for Tubularia. I found (Archiv f. Entwickelungsmechanik, ix. 1899), that a reduction of the length of the stem is always followed by a reduction of the size of the hydranth-primordium, but there is no real proportionality between them. It is only for theoretical simplification that a strict proportionality is assumed here, both in the text and the diagram. But there is an almost strict proportionality in all cases of “closed forms.”