. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. COLD-HARDINESS IN FUCUS 475 stoppered jars of fresh sea water, and taken to the laboratory within 30 minutes. Fronds three inches long, including reproductive tips as well as vegetative ones, were cut from these plants, blotted on filter paper, and put in 500-ml. Dewar flasks in a damp condition. These were stoppered with a cork and cooled by an ethane com- pression system in a low temperature apparatus having a two-foot square compart- ment (Parker, 1959). The ethane, in turn, was cooled by a Freon-22 compressor system (Cin
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. COLD-HARDINESS IN FUCUS 475 stoppered jars of fresh sea water, and taken to the laboratory within 30 minutes. Fronds three inches long, including reproductive tips as well as vegetative ones, were cut from these plants, blotted on filter paper, and put in 500-ml. Dewar flasks in a damp condition. These were stoppered with a cork and cooled by an ethane com- pression system in a low temperature apparatus having a two-foot square compart- ment (Parker, 1959). The ethane, in turn, was cooled by a Freon-22 compressor system (Cincinnati Sub-Zero Products, Ohio). After being cooled at a rate of 20 10. -10 -20 -30 -40 -50 -60 _L f • • o I i O _L N M M FIGURE 1. Upper curves represent maximum and minimum temperatures at the New Haven municipal airport, averaged for each month for the 1959-1960 season. Lower curve (dashed) represents the relative hardiness of Fucus, drawn rather freely as the approximate point at which 50% of the frond was alive (reducing tetrazolium chloride). Data are given in Table I. Blacked-in circles represent temperatures to which a group of plants were cooled on a particular day. 4° C. per hour to one of the temperatures indicated by the blacked-in circles in the results (Fig. 1), flasks were removed to an ordinary refrigerator for three hours and then to room air to obtain a warming rate of about 8° C. per hour. Determination of viability by ordinary means, for example by leaf color, is very difficult in these marine algae and may account for the lack of research in this field. But by means of the tetrazolium test, very clear and reliable results could be ob- tained. The fact that reduction of this compound by dehydrogenases to its red formazan derivative is a good indication of cellular viability has been previously. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these
Size: 3252px × 768px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
