. The biology of the Protozoa. Protozoa; Protozoa. EFFECTS OF REORGANIZATION ON VITALITY 565 in the Table, p. 560 by an asterisk. The vitahty of the first sixty days of a cyst series is compared with that of the parent series for the sixty days following encystment and the results are practically the same as with ex-conjiigants. In some cases the cysts are kept dried for a period of weeks or months but this has no effect upon the vitality of the organism when it emerges. In all cases the evidence of rejuvenescence is the same as for ex-conjugants from young series. The general results of these
. The biology of the Protozoa. Protozoa; Protozoa. EFFECTS OF REORGANIZATION ON VITALITY 565 in the Table, p. 560 by an asterisk. The vitahty of the first sixty days of a cyst series is compared with that of the parent series for the sixty days following encystment and the results are practically the same as with ex-conjiigants. In some cases the cysts are kept dried for a period of weeks or months but this has no effect upon the vitality of the organism when it emerges. In all cases the evidence of rejuvenescence is the same as for ex-conjugants from young series. The general results of these experiments with Uroleptus mobilis leave little groand for reasonable doubt of the rejuvenating effect of conjugation. The view of Woodruff and Spencer (1924) that loss of vitality and death here are due to conditions of the milieu seems rather far-fetched when we consider that series after series with the similar sequence of renewed, waning, and exhausted. Fig. 233.—Kanjamceba falcata. (After Kofoid and Swezy.) vitality pass by in ai)parently endless succession, and all in the same milieu so far as it is possible to make it the same, from the beginning of the experiments eight years ago to the present. • It is quite a different question whether or not conditions of the medium can be so altered as to bring about the same results as conjugation. The explanation must be looked for in the protoplasmic happenings at the period of conjugation or of endomixis (see Chapter XI). In both cases these result in a rearrangement of the chromatin and cytoplasm which according to Erdmann (1921) gives rise to new sets of autocatalyzers and new cytoplasmic matrices for their activation. Nothing is known about the effect of encystment on vitality in the Sarcodina or Mastigophora. There is no a yriori reason to doubt that as in ciliates reorganization is accomplished during. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readabi
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