. The microscope and its revelations. itnuutl in the intestinalcanal of the lobster) in (Jinirt. Juiini. Mi<-,-<ia<-. Sci. \1. x. , p. 51, and p. 24-2. 75O MICROSCOPIC FORMS OF ANIMAL LIFE—PROTOZOA circular row of booklets, closely resembling that which is seen onthe head of Tfenia. There is here a much more complete differentia-tion between the cell-membrane and its contents than exists eitherin Actinophrys or in Amoeba ; and in this respect we must look uponGregarina as representing a decided advance in organisation. Beingnourished upon the juices already prepared
. The microscope and its revelations. itnuutl in the intestinalcanal of the lobster) in (Jinirt. Juiini. Mi<-,-<ia<-. Sci. \1. x. , p. 51, and p. 24-2. 75O MICROSCOPIC FORMS OF ANIMAL LIFE—PROTOZOA circular row of booklets, closely resembling that which is seen onthe head of Tfenia. There is here a much more complete differentia-tion between the cell-membrane and its contents than exists eitherin Actinophrys or in Amoeba ; and in this respect we must look uponGregarina as representing a decided advance in organisation. Beingnourished upon the juices already prepared for it by the digestiveoperations of the animal which it infests, it has no need of any such.•ipparatus for the introduction of solid particles into the interior ofits body, as is provided in the pseudopodia of the rhizopods andin the oral cilia of the Infusoria. Within the cavity of the cell,whose contents are usually milk-white and minutely granular, therea pellucid nucleus; and when, as often happens, is generally seen. Fi<;. 58-2.—Cyst of Monocystis soluble in acetic acid. The move-ments of the body are of very various kinds; there is a forwardmovement which may be due. as suggested by Lankester, to theundulations oftbe body. The cell itself may undergo contraction, andconsequent change in form, which may, or may not. lie accompaniedby locomotion; circular constrictions may extend along the body;or Ilie cell may bend on itself and again straighten out. By VanUeneilen the contractility of the cell is localised in a layer of the SPOKOZOA 751 ectoplasm, the so-called myocyte which he has found to consist ofa layer of contractile fibrils. When the process
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectmicrosc, bookyear1901
