. The biology of the Protozoa. Protozoa; Protozoa. NUCLEI AND KINETIC ELEMENTS 65 similar size and are densely packed throughout the entire nucleus, giving a characteristic appearance after staining. They are widely distributed in Dinoflagellata, Ciliata and Suctoria, but there is con- siderable variation in their density in different species, especially in the Infusoria. In some of the micronuclei {e. g., Paramecium caudaUim, Euplotes patella, etc.), the chromidiosomes are so tightly packed as to give them, more than any other type of protozoon nucleus, the aspect of a spermatozoon head (Fig.
. The biology of the Protozoa. Protozoa; Protozoa. NUCLEI AND KINETIC ELEMENTS 65 similar size and are densely packed throughout the entire nucleus, giving a characteristic appearance after staining. They are widely distributed in Dinoflagellata, Ciliata and Suctoria, but there is con- siderable variation in their density in different species, especially in the Infusoria. In some of the micronuclei {e. g., Paramecium caudaUim, Euplotes patella, etc.), the chromidiosomes are so tightly packed as to give them, more than any other type of protozoon nucleus, the aspect of a spermatozoon head (Fig. 22, Z), E, F). In other cases the granules are very fine and follow the course of the linin network thus affording an excellent picture of the alveolar structure within the Fig. 27.—Chromidia formation in Mastigella and Mastioina. A, B, young forms of Mastigella vitrea prior to chromidia formation; C, chromidia arising from the nucleus D, young form of Mastigina setosa with accumulation of chromidia; E, F, mature stages of M. setosa; G, formation of gametic nuclei (a) from scattered chromidia. (After Goldschmidt.) The formation of the massive tApe of nucleus during reorganiza- tion after conjugation is clearly shown in the case of Uroleptus mobilis (Fig. 1, Frontispiece). The young macronucleus is formed by a second division of a fertilization nucleus after conjugation when it appears as a vesicular nucleus with a fine linin reticulum which has no staining capacity. In life it appears like a large, highly refractile, vacuole. It remains in this ghost-like condition for a period of three or four days, enlarging meanwhile and becoming ellipsoidal in form. Chromatin ultimately makes its appearance in the form of minute granules on the nuclear reticulum. These granules increase in number and in size until the characteristic dense nucleus with intense staining capacity results (Fig. 2S). It then divides with the. Please note that these images are extracted from scanned
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Keywords: ., bookauthorcalkinsgaryngarynatha, bookcentury1900, bookdecade1920
