. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 20 JOHN BUCK without attempting to ascertain the cause of the differences or whether they are in fact consistently seasonal or geographically distinct. For visual observation colonies were studied at magnifications up to 100 X in four-inch finger howls of standing sea water. Since it is known that ambient light can inhibit luminescence, colonies were dark-adapted for at least a half hour before testing. Colonies were stimulated r/</ condenser shocks of 100 msec duration and nominal strengths up to 80 volts. Click-stop con
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 20 JOHN BUCK without attempting to ascertain the cause of the differences or whether they are in fact consistently seasonal or geographically distinct. For visual observation colonies were studied at magnifications up to 100 X in four-inch finger howls of standing sea water. Since it is known that ambient light can inhibit luminescence, colonies were dark-adapted for at least a half hour before testing. Colonies were stimulated r/</ condenser shocks of 100 msec duration and nominal strengths up to 80 volts. Click-stop control knobs enabled stimulus parameters to be set in total darkness. The electrode consisted of two strands of no. 24 enameled ^11 •* .. 4? \ ,-. FIGURE 1. Portions of living Rcnilla rachis in sea water, X3; (a), expanded colony; (b), contracted colony; SZC, siphonozooid cluster; AZ. expanded autozooid polyp; AZC, calyx or base of autozooid. copper wire sealed in a glass tube except for the tips, 3 mm apart. The bare metal was cleaned periodically with a carborundum stick to reduce fouling by mucus. The electrode was carried on a sliding rack so that it could be lowered to the rachis in total darkness by feel. The electrode was usually positioned about a third of the distance in from the margin of the rachis to the center and was pressed firmly into the surface to prevent shifts in position due to peristalsis or deflation. Voice descriptions of behavior were tape-recorded concurrently with the stimulus signals. Water temperatures varied between 20° and 25°. Since the absolute intensity of Rcnilla luminescence is low, care was taken to dark-adapt the eyes for at least 20 minutes before beginning 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. )
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
