Note 320 — Chapter VIII · THE DIGESTIVE ORGANS, JAW, AND RADULA: EXCRETORY ORGANS
Reading edition
The mechanism of the radula has been dealt with by Geddes, Trans. Zool. Soc. x. p. 485. Rücker has observed (Ber. Oberhess. Gesell. Nat. Heilk. xxii. p. 207) that the radula in Helix pomatia is the product of five rows of cells; the use of the first row is uncertain, the second forms the membrane of the radula, while rows three to five originate the teeth.