Note 42 — PART I.—MORPHOLOGY AND PHYSIOLOGY (continued 5)
Reading edition
The arthropod protocerebrum probably represents the annelid brain (supraœsophageal ganglion). The antennal segment (deutocerebrum), with the premandibular (intercalary) segment (tritocerebrum) originally postoral, have, as Lankester suggests, in the Arthropoda moved forward to join the primitive brain. See Wheeler, Journ. Morphology, Boston, viii, p. 112.