. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. i68 ARTHUR WHITE stant temperatures, ranging from i° to 10° C., could be main- tained. For each low temperature experiment, a control experi- ment was performed at the temperature of the room, and great care was taken that all the conditions, with the exception of temperature, might be identical in the two cases. Monas is more sensitive to changes in the temperature than any of the other Protozoa experimented with. Within a few hours after the temper- ature has been lowered to 4 ° C. all the Monads in a dish settle
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. i68 ARTHUR WHITE stant temperatures, ranging from i° to 10° C., could be main- tained. For each low temperature experiment, a control experi- ment was performed at the temperature of the room, and great care was taken that all the conditions, with the exception of temperature, might be identical in the two cases. Monas is more sensitive to changes in the temperature than any of the other Protozoa experimented with. Within a few hours after the temper- ature has been lowered to 4 ° C. all the Monads in a dish settle to the bottom, and cease their progressive movement. At same time the cell gradually becomes spherical, the fla- gellum and mouth opening disappear, Fi<;. 2. A resting cell of Monas, and there is formed a resting cell like formed by an exposure to a tern- those alread described ih the experi- perature of 4° C. during six hours. ments upon Stentor. These resting cells can be kept at a temperature of 4° to 6° C. indefinitely, and will withstand partial desiccation without losing their power to revert to the normal Fionas form when they are removed to the temperature of the room. This reversion to the motile form takes place within twenty-four hours after the room temperature has been reached. Theflagellum first its appearance, and the cells be- come motile while still in the spher- ical conpition. They soon, how- ever, assume the normal elongated form of the adult Monas. If these resting cells of Monas FIG. 3. The formation of spores which have been formed at a tern- within the restin§ cel1' after an ex' posure to a temperature of 1° C. for perature of 4° to 6 C., instead five days of being returned to the temper- ature of the room, be placed on ice at a temperature of i° C. further structural changes take place as a result of this ex- treme lowering of the temperature. After remaining at a tern-. Please note that these images are extracted from scanned page
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
