. A text book of veterinary pathology, for students and practitioners. Veterinary pathology. GENERAL COXSIDERATION OF DISICASE. 63 Protozoa. Protozoa are microscopic single celled animals. They arc very simple in structure, being composed of a mass of proto- plasm with or without a cell membrane. The cell membrane, when present, consists of concentrated protoplasm. The pro- tozoa having a cell membrane are constant in shape, as the Try- panosoma Evansi, and those not possessing a cell membrane vary in shape from a sphere to an irregular flat mass and are capable of changing their shape wheneve
. A text book of veterinary pathology, for students and practitioners. Veterinary pathology. GENERAL COXSIDERATION OF DISICASE. 63 Protozoa. Protozoa are microscopic single celled animals. They arc very simple in structure, being composed of a mass of proto- plasm with or without a cell membrane. The cell membrane, when present, consists of concentrated protoplasm. The pro- tozoa having a cell membrane are constant in shape, as the Try- panosoma Evansi, and those not possessing a cell membrane vary in shape from a sphere to an irregular flat mass and are capable of changing their shape whenever occasion demands. Protozoa are larger than i'l— Evansi in 3 blooflsmear from a horse affected with surra. Protozoa require food similar to the foods of higher animals. Particles of food are inchjsed or incorporated by them prepara- tory- to digestion. Digestion is accomplished by means of fer- ments elaborated and secreted by the protozoa. The digested foods pass bv osmosis into the protozoa, the undigested por- tion being extruded by rearrangement of the cell protoplasm. Respiration takes place by exchange of gases through the surface protoplasm of the protozoa. They reproduce bv fission, budding, ctmjugation or sporulation. Protozoa are universallv distributed. They all require con- siderable moisture. In fact most of them live either in fresh or salt water. A few only are parasitic. The specific action of pathogenic protozoa in the produc- tion of disease is not understood. Some mav have a mechanical efl:'ect only out the evidence concerning others indicates that most of them produce an injurious chemic substance. Helmintbes. This branch of the animal kingdom contains manv species that are parasitic. .Structural, animal parasites are much simpler. 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
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectveterin, bookyear1910
