. Elementary text-book of zoology, tr. and ed. by Adam Sedgwick, with the assistance of F. G. Heathcote. JUIIZOPODA. 181 by holes, to shelter and protect the body (Foraminiferd, Radiolaria). In the Infusoria, the sarcode body is bounded by an external mem- brane, and is capable of quick and varied locomotion by means of the movements of the cilia, hairs, bristles, etc., which it possesses. The solid nourishing matter is taken in through a mouth, and the remainder, after digestion, passes out through an anal aperture. CLASS I.— RHIZOPODA.* Protozoa without external investing membrane, the paren
. Elementary text-book of zoology, tr. and ed. by Adam Sedgwick, with the assistance of F. G. Heathcote. JUIIZOPODA. 181 by holes, to shelter and protect the body (Foraminiferd, Radiolaria). In the Infusoria, the sarcode body is bounded by an external mem- brane, and is capable of quick and varied locomotion by means of the movements of the cilia, hairs, bristles, etc., which it possesses. The solid nourishing matter is taken in through a mouth, and the remainder, after digestion, passes out through an anal aperture. CLASS I.— RHIZOPODA.* Protozoa without external investing membrane, the parenchyma of which protrudes and retracts processes ; as a rule, a calcareous shell or silicious skeleton is secreted. The body-substance of these animals, the shells of which were described as Foraminifera or Polythalamia, long before their living contents were known, consists of sarcode, and is without any boundary mem- brane. The body- substance, which is richly granulated and contains pig- nient, contracts slowly and sends out at the same time fine thread -like rays (fi^ 120) for the most part of a semi-fluid cons is te ncy (pseudopodia} ; and these serve not only as a means of movement but also for the reception of nourishment. The pseudopodia may, how- * Dujardin, "Observations sur les Rhizopodes" (Comptes rendits, 1835). Ehrenberg. " Tiber noch jetzt zahlreich lebende Thierarten der Kreidebildung und den Organisms der Polythalamien" (Abhandlung der AJtad. ru Berlin^ 1839). Max Sigin. Schultze, " Uber den Organismus der Polythalamien" (Leipzig, 1854). Joh. Miiller. " Uber die Thalassicolen, Polyoystinen und Acan- thometfen" (1858). E. Haeckel, "Die Radiokrien" (Eine Monographic. Berlin, 1 862).. Flr" 120.— Optical section through portion of the sarccde body of Actinosphaerium Eichhornii (after Hertwig and Leaser). N, nuclei jn t,ne endosarc, from which the vacuolated ectoaarc ifl clearly dis- tinguishable. In the cent
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