. Protozoo?logy. Protozoa; Protozoa, Pathogenic. 260 THE PATHOGENIC FLAGELLATES infected with Tryp. indicum, or Holmes in connection with Tryf. evansi, are regarded as normal stages in the life history of the organism. From the meagre account of the English observers these appear to be nothing more than the nucleus of the cell with a very small layer of protoplasm about it; in rats they become stored up in the spleen and bone ma,rrow, and the authors believe that they ultimately give rise to adult organisms in much the same way that crithidia or herpetomonas is metamorphosed from the resting s
. Protozoo?logy. Protozoa; Protozoa, Pathogenic. 260 THE PATHOGENIC FLAGELLATES infected with Tryp. indicum, or Holmes in connection with Tryf. evansi, are regarded as normal stages in the life history of the organism. From the meagre account of the English observers these appear to be nothing more than the nucleus of the cell with a very small layer of protoplasm about it; in rats they become stored up in the spleen and bone ma,rrow, and the authors believe that they ultimately give rise to adult organisms in much the same way that crithidia or herpetomonas is metamorphosed from the resting stage into a flagellate. Without further evidence such phases may be interpreted as special reactions to abnormal conditions rather than stages in the ordinary life history. Fig. 102. Trypanosoma gambiense; stages in longitudinal division, preparation by F. W. Baeslack. Original from a D. Reproduction.—Reproduction by division is easily observed in all types of trypanosomes, and seems to follow a similar method throughout, the details varying in some cases. As in herpetomonas,- it is inaugurated by the division of the kinetic elements of the cell, the flagellum dividing first, according to some observers (e. g., T. gam- hlense, according to Minchin), the kinetonucleus dividing before the nucleus, the latter dividing as does the centronucleus of free flagellates. Abnormal division figures are frequently observed, due to the division of nuclei and the formation of new flagella before the cell body splits. As in spirochetes, the daughter cells in the last stage of division are connected only at one end—in this case the anterior or kinetonucleus. 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. New York and Philadelphia, Lea & Febiger
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