Regardless, he seemed quite certain that ameboid cells
played an essential role in the crystallization of both shell nacre and pearls, the former stimulated by normal growth processes and the latter by the abnormal presence of a foreign object.
The endothelium in inflammation forms new capillary sprouts; it may also proliferate and give off cells into the tissue which at once assume the characters of fibroblasts; but its elements never become transformed into ameboid cells
In this fashion, apoplastic nutrient transport by ameboid cells
has become specialized in the genus Aplysina to the extent that these sponges have a differentiated structure that parallels fluid transport systems in other animals, but is a typically novel poriferan solution.