. The effects of inanition and malnutrition upon growth and structure . I—cr. Figs, i to 6.—Paramecia in various stages of inanition. Figs, i to 5 from Lipska ('10); Fig. 6 from Wallengren ('02). Magnification about X400. , buccal groove; c, cilia; cr, excretion crystals; , degeneration vacuoles; ect., ectoplasm; end., endoplasm;/., fold in body; , food vacuoles; TV, macronucleus; n, micronucleus. Fig. 1.—:Normal Paramecium caudalum of average dimensions. Fig. 2.—Paramecium after six days of inanition. The macronucleus (TV) is greatly enlarged, occupying the posterior half of the p
. The effects of inanition and malnutrition upon growth and structure . I—cr. Figs, i to 6.—Paramecia in various stages of inanition. Figs, i to 5 from Lipska ('10); Fig. 6 from Wallengren ('02). Magnification about X400. , buccal groove; c, cilia; cr, excretion crystals; , degeneration vacuoles; ect., ectoplasm; end., endoplasm;/., fold in body; , food vacuoles; TV, macronucleus; n, micronucleus. Fig. 1.—:Normal Paramecium caudalum of average dimensions. Fig. 2.—Paramecium after six days of inanition. The macronucleus (TV) is greatly enlarged, occupying the posterior half of the pear-shaped body. Fig. 3.—Paramecium after seven days of inanition. The macronucleus (TV) is elongated; micronucleus (w) emigrated to posterior end of body. Two depressions are visible on the body, separated by a thick ridge or fold (/). mecia were finally fixed, stained and mounted for more detailed microscopic study. The results, in comparison with those of her predecessors, will be sum- marized briefly (Figs. 1 to 5). The average duration of life under such conditions was found by Lipska to be only five to seven days. The time varies according to circumstances, however. The (exhausted?) individuals starved immediately after conjugation survive only about three days. A few individuals, especially those containing symbiotic green algae, may survive ten or twelve days; and those previously hypernour- ished may survive even fifteen to twenty days. The higher averages of pre- vious observers represent merely the few survivors of an incomplete inanition.
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Keywords: ., bookcentury1900, bookdecade1920, bookpublis, booksubjectnutrition
