Note 122 — Chapter XIII
Reading edition
J. Parker, “On the Histology of Hydra fusca,” Quart. Journ. Micr. Science, vol. XX. 1880; and El. Metschnikoff, “Ueb. die intracelluläre Verdauung bei Cœlenteraten,” Zoologischer Anzeiger, No. 56, vol. III. 1880 and Lankester, “On the intracellular digestion and endoderm of Limnocodium,” Quart. Journ. Micr. Science, vol. XXI. 1881.