[12] Morren, ‘De Lumbrici terrestris Hist. Nat.’ &c., 1829, p. 67.
[14] ‘De Lumbrici terrestris Hist. Nat.’ &c., p. 14.
[17] Histolog. Untersuchungen über die Regenwürmer. ‘Zeitschrift für wissenschaft. Zoologie,’ B. xix., 1869, p. 611.
[18a] For instance, Mr. Bridgman and Mr. Newman (‘The Zoologist,’ vol. vii. 1849, p. 2576), and some friends who observed worms for me.
[18b] ‘Familie der Regenwürmer,’ 1845, p. 18.
[31] ‘The Zoologist,’ vol. vii. 1849, p. 2576.
[32] ‘Familie der Regenwürmer,’ p. 13. Dr. Sturtevant states in the ‘New York Weekly Tribune’ (May 19, 1880) that he kept three worms in a pot, which was allowed to become extremely dry; and these worms were found “all entwined together, forming a round mass and in good condition.”
[33] ‘De Lumbrici terrestris Hist. Nat.’ p. 19.
[34] ‘Archives de Zoologie expérimentale,’ tom. vii. 1878, p. 394. When I wrote the above passage, I was not aware that Krukenberg (‘Untersuchungen a. d. physiol. Inst. d. Univ. Heidelberg,’ Bd. ii. p. 37, 1877) had previously investigated the digestive juice of Lumbricus. He states that it contains a peptic, and diastatic, as well as a tryptic ferment.
[35a] On the action of the pancreatic ferment, see ‘A Text-Book of Physiology,’ by Michael Foster, 2nd edit. pp. 198–203. 1878.