. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. I/O ARTHUR WHIEE FIG. 5. Young Monads devel- oped from the spores within the old cell wall of the resting cell. swims away, leaving the empty spore behind. In some cases the spores are not discharged from the resting cell as soon as they are formed, but develope within its walls, so that it is possible to find spores in all stages of development, even the young Monads, within the old rest- ing cell. The development of the spores usually occupies from two to four days, although in some cases it may be delayed for a
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. I/O ARTHUR WHIEE FIG. 5. Young Monads devel- oped from the spores within the old cell wall of the resting cell. swims away, leaving the empty spore behind. In some cases the spores are not discharged from the resting cell as soon as they are formed, but develope within its walls, so that it is possible to find spores in all stages of development, even the young Monads, within the old rest- ing cell. The development of the spores usually occupies from two to four days, although in some cases it may be delayed for a mcuh. longer time. The Monads formed from the spores are at first spherical, and swim about with the characteristic revolv- ing movement of this species of Mo- nas. The cells rapidly become elon- gated, however, and within a short time are indistinguishable in all re- spects from the adult organism. A few typical experiments will be briefly described, as fol- lows :-^ Experiment I.—On April i i a culture of Monas was placed in the refrigerator at a temperature of i° to 4°C. The next day examination showed that all the Monads had formed spherical resting cells. Some of these were removed to the temperature of the room, and they immediately developed into the motile form. On April 24 many of the resting cells had broken up into spores. A small number of these resting cells and spores were isolated under the microscope. The resting cells imme- diately developed into the motile Monads as before. On April 26 a few of the spores had formed small Monads, but the de- velopment did not go very far because of a lack of oxygen in the closed cells which contained the spores. Experiment II.—On April 18 a culture of Monas was put on ice at a temperature of i° C. On May 3 the culture was removed to a temperature of 6° C. A large number of spores had been formed, a large proportion of them remaining within the resting, cells. On May 6 many of the spores had devel- oped into young Monad
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
