. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CELLULASK IN D1PLODINIUM 309 stages of the culture and the fact that they died if not transferred on schedule, suggested that the cultures were less favorable for growth in the later stages. Consequently it was anticipated that a more rapid division rate would be observed if the transfers were made more fre- quently. In order to test this, a second series of cultures with daily transfers was run in parallel to the first. 1500 r 1000 <u 0. 01 o N O fc 500 o S3. 5 10 Days FIGURE 1. Concentration of protozoa. The results of
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CELLULASK IN D1PLODINIUM 309 stages of the culture and the fact that they died if not transferred on schedule, suggested that the cultures were less favorable for growth in the later stages. Consequently it was anticipated that a more rapid division rate would be observed if the transfers were made more fre- quently. In order to test this, a second series of cultures with daily transfers was run in parallel to the first. 1500 r 1000 <u 0. 01 o N O fc 500 o S3. 5 10 Days FIGURE 1. Concentration of protozoa. The results of the second series are shown as broken lines in Figure 1. It may be seen that after an initial drop in concentration as compared with the 48-hour series the division rate increased sufficiently to main- tain and even to increase slightly the concentration of protozoa at each 24-hour transfer. It follows that on the average a division occurred at least once each day. 6. Purification of the Protozoa A preliminary attempt was made to grow the protozoa free of bac- teria but it was unsuccessful. The wash methods which have been used to obtain pure cultures of other protozoa present special difficul- ties in the case of Eudiplodinium. It is necessary to maintain a suitable temperature of the wash medium and to prevent exposure to oxygen. Special anaerobic wash dishes were constructed and single protozoa were washed through as many as five transfers. They ceased moving at or before the fifth transfer and settled on the bottom. Such in- dividuals failed to divide even though sterile grass and cellulose were present. On the other hand, in three different instances a single indi-. 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
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
