[55] Vorlesungen über allgemeine, Pathologie, Vol. I, 1882.
[56] Handbuch.
[57] Handbuch d. allgem. Pathologie, 1879.
[58] Allgemeine Pathologie, Vol. II, 1889.
[59] Über Endothelwucherungen in Arterien. Beitr. z. pathol. Anat., Vol. VIII, 1890.
[60] Haeckel (1870) first showed, in another medusa, that pieces produce new medusæ.
[61] In rodents, however, the incisors continue to grow throughout the life of the animal.
[62] If the young worm is fed the new part becomes almost as broad as the old piece, but if the worm is not fed the old part decreases in breadth and the new part does not grow as broad as in the former case.
[63] See Fraisse for literature.
[64] In the figure one double or forked toe is present.