. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. LONGEVITY IN PROTOZOAN PROTOPLASM 423 test" is started. Here the individuals multiply by division until there may be thousands in the container. In the early stages of the life cycle of Urolcptus inobilis all such individuals ultimately die of starvation, but after approximately a month or six weeks after conjugation such tests result in an increasing number of encystments. A type of cataly- sis which is not seen in the division phenomena is now manifested. The macronucleus is broken down by fragmentation and the fragme
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. LONGEVITY IN PROTOZOAN PROTOPLASM 423 test" is started. Here the individuals multiply by division until there may be thousands in the container. In the early stages of the life cycle of Urolcptus inobilis all such individuals ultimately die of starvation, but after approximately a month or six weeks after conjugation such tests result in an increasing number of encystments. A type of cataly- sis which is not seen in the division phenomena is now manifested. The macronucleus is broken down by fragmentation and the fragments are absorbed in the protoplasm while a new macronucleus is formed from a product of micronuclear division. Other structures of the derived or-. FIG. 6. Glaucoma (Dallasia) frontata. History of a normal vegetative indi- vidual with successive divisions resulting in copulating gametes and encysted zygotes (see Calkins and Bowling, 1929). ganization are absorbed, waste matters and water are voided to the out- side, and a cyst membrane is formed within which the organism may remain in a desiccated condition for months. When it is brought out of the cyst and established in isolation culture, it has an optimum vitality and passes through a complete life cycle exactly like that of an ex-con- jugant. This phenomenon of endomixis, except for encystment, is the same as endomixis in Paraincciitin aitrclia originally described by Wood- ruff and Erdmann (1914). Endomixis thus brings about a more far- reaching and a more complete reorganization than does division, and the important derived structure, the macronucleus, is 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 Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annual report 1907/08-1952; Lillie, Fran
Size: 1851px × 1350px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
