{18b} Familie der Regenwurmer, 1845, p. 18.
{31} The Zoologist, vol. vii. 1849, p. 2576.
{32} Familie der Regenwurmer, 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 experimentale, 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.
{35b} Schmulewitsch, Action des Sucs digestifs sur la Cellulose.
Bull. de l Acad. Imp. de St. Petersbourg, tom. xxv. p. 549. 1879.
{40} Claparede doubts whether saliva is secreted by worms: see
Zeitschrift fur wissenschaft. Zoologie, B. xix. 1869, p. 601.
{41a} Perrier, Archives de Zoolog. exper. July, 1874, pp. 416, 419.
{41b} Zeitschrift fur wissenschaft. Zoologie, B. xix, 1869, pp.
603 606.
{46} De Vries, Landwirth. Jahrbucher, 1881, p. 77.
{49} M. Foster, A Text-Book of Physiology, 2nd edit. 1878, p. 243.
{50} M. Foster, _ut sup._ p. 200.
{53} Claparede remarks ( Zeitschrift fur wisseuschaft. Zoolog. B. 19,
136