Fig. 7 in Morphogenetic gradients in graptolites and bryozoans

Fig. 7. Diagram showing two patterns of regeneration in fragmented graptoloid colonies. A. Primary rhabdosome subject to fragmentation (as indicated by wavy line) into the proximal and distal portions. B. Regeneration from the proximal fragment of the primary rhabdosome resulting in a unipolar regenerative morphosis (single arrow), with a distal regenerative portion showing an abrupt increase in the size of zooidal tubes (thecae). C. Regeneration from the distal fragment of the primary rhabdosome resulting in a bipolarly growing morphosis (two arrows) due to formation of the regenerative proximal portion growing (solid arrow) simultaneously with the preserved distal tip of the primary rhabdosome (broken arrow); S, scar or traces of fracture, regenerated portions obliquely hatched.