American journal of physiology . again becomes normalthese resting cells undergo a reverse process, and become activeStentor. This retransformation of the artificially produced restingcells into the normal animals was observed to be complete in three orfour cases. In several cases, although the first stages of the processwere seen, the retransformation was never completed. In all in-stances, the resting cells lived in the small dishes for from two tothree weeks before disintegrating, showing that the Stentor hadnot been immediately killed by the low temperature. In the fewinstances in which th
American journal of physiology . again becomes normalthese resting cells undergo a reverse process, and become activeStentor. This retransformation of the artificially produced restingcells into the normal animals was observed to be complete in three orfour cases. In several cases, although the first stages of the processwere seen, the retransformation was never completed. In all in-stances, the resting cells lived in the small dishes for from two tothree weeks before disintegrating, showing that the Stentor hadnot been immediately killed by the low temperature. In the fewinstances in which the complete retransformation was observed, thespherical resting cells were removed from the cold water by means ofa pipette, and isolated in small covered dishes at the room tempera-ture. In from three to six hours after removal from the cold water theretransformation was begun by the cell gradually lengthening until itassumed the form of an ordinary Stentor. The nucleus appeared as Loss of Water and Lowering of Temperature. 125. a solid band (;/, Fig. 5) formed by the fusion of the nuclear nodes,but it slowly divided until the common chain-like form was first indication of the peristomal cilia was a longitudinal ciliatedband (/ c, Fig. 5) which extended over the an-terior end of the cell. The lower end formed aslight spiral depression which grew deeper, andfinally became the mouth {in, Fig. 5). The upperend of this ciliated band curved slowly about theanterior portion of the animal and at the sametime the lower end with the mouth depressionwas drawn up, until the band formed a circlearound the anterior end of the cell with themouth at one side {jn, Fig. 6). This circle be-came the peristomal circle of cilia (/> c, Fig. 6),inclosing the disk or peristome (/, Fig. 6). Thecilia extended spirally down the mouth, formingthe cilia of the gullet. While these changeswere taking place the ectosarc and its striationsappeared, and a typical Stentor resulted. These stages in
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