compared with statoblasts, [493]
Woodworth, on yolk-glands, [38] n.
Wreath, in Rotifers, [200]
Wright, on Phoronis, [450], [456]
Yellow-cells, in Leptoplana, [13]
Yolk-gland, in Planaria, [38], [39];
in Rhabdocoelida, [47];
in Temnocephala, [54];
in Polystomatidae, [57];
in Calliobothrium, [75];