. The biology of the Protozoa. Protozoa; Protozoa. 154 BIOLOGY OF THE PROTOZOA The tentacle, then, with prey attached, is withdrawn entirely into the body, the Halteria is worked around to the mouth and swal- lowed (Fig. 81). In Didinium nasvtum the proboscis bears a peculiar protrusible plug or tongue of protoplasm termed the "seizing organ" by Thon (1905) and Prandtl (1907) (Fig. 89, 8). A zone of trichocyst-like fibrils lies near the extremity of this plug and when certain types of ciliates, preferably Paramecium, are struck by Didinium the plug, with trichocysts, is shot out pene
. The biology of the Protozoa. Protozoa; Protozoa. 154 BIOLOGY OF THE PROTOZOA The tentacle, then, with prey attached, is withdrawn entirely into the body, the Halteria is worked around to the mouth and swal- lowed (Fig. 81). In Didinium nasvtum the proboscis bears a peculiar protrusible plug or tongue of protoplasm termed the "seizing organ" by Thon (1905) and Prandtl (1907) (Fig. 89, 8). A zone of trichocyst-like fibrils lies near the extremity of this plug and when certain types of ciliates, preferably Paramecium, are struck by Didinium the plug, with trichocysts, is shot out penetrating the cortex of the prey and paral;\'zing it. While this process takes place too rapidly to be seen the results show that it must have taken place for, after striking and anchoring in the Paramecium, the seizing organ with prey. Fig. 81.—Actinobolus radians St. (After Moody.) attached is retracted and the prey, often larger than the captor, is swallowed whole (Fig. 89). No satisfactory explanation of this phenomenon has yet been given. Still another type of cortical organs is illustrated by the various kinds of tentacles of the Suctoria. Some of these are constructed for piercing, while others are hollow, forming sucking tubes through which food is taken into the body. They are evidently provided with some type of poison for active ciliates, coming in contact with these tentacles, become suddenl,\' quiet and remain so while the suctorial tentacles penetrate the cortex and suck out the endoplasm of the prey which can be followed through the feeding tubes to the endoplasm of the captor (Maupas, 1883). Like the tentacles of. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Calkins, Gary N. (Gary Nathan), b. 1869. Philadelphia, New York, Lea & Febiger
Size: 1614px × 1548px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorcalkinsgaryngarynatha, bookcentury1900, bookdecade1920
