. The biology of the Protozoa. Protozoa; Protozoa. STRUCTURAL DIFFERENTIATIONS 137 flagellates represent the furrow— which separates an epitheca or upper, from the hypotheca or lower part of the shell—with a fringe of cilia, and the name Cilioflagellata given to the group, indicates the extent to which this view prevailed. In some aberrant types like ExnvioeUa marina, in which there is no transverse groove, the "transverse" flagellum makes a sharp bend near the anterior end of the body and vibrates in a circle exactly as though it were still confined within a transverse groove (Fig.
. The biology of the Protozoa. Protozoa; Protozoa. STRUCTURAL DIFFERENTIATIONS 137 flagellates represent the furrow— which separates an epitheca or upper, from the hypotheca or lower part of the shell—with a fringe of cilia, and the name Cilioflagellata given to the group, indicates the extent to which this view prevailed. In some aberrant types like ExnvioeUa marina, in which there is no transverse groove, the "transverse" flagellum makes a sharp bend near the anterior end of the body and vibrates in a circle exactly as though it were still confined within a transverse groove (Fig. 71).. A B Fig. 71.—Exuvicella marina (A) and E. lima (B). (After Calkins.) Delage and Herouard have attempted to explain the dynamics of flagellum action whereby the comparatively heavy body is moved forward by reason of the vibrations of the exceedingh' delicate thread. In the usual type the extremity of the flagellum describes a rather wide circle so that it is in a certain focus of the microscope for only an instant of time. With this circular movement, which varies in dift'erent species, constant undulations pass from the base to the tip. A forward pull results from the combination of such movements and the cell either glides smoothly after its active pro- peller, as in Peranema trichophora, or Euglena , etc., or rotates more or less rapidly on its long axis while freely swimming. 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: 1344px × 1859px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorcalkinsgaryngarynatha, bookcentury1900, bookdecade1920
