402 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1959 
thing studied in our laboratory during the past 3 years—from carrots 
to seaweed, and from crabs and oysters to rats—has shown this 
capacity to predict very safely beyond chance the barometric pressure 
changes usually 2 days in advance. It is interesting to contemplate 
the problem of a meteorologist sealed, incommunicado, for weeks or 
months in constant conditions, and asked to give 2-day weather pre- 
dictions—or for that matter even to tell you the weather today. 
The potatoes also indicate to us that they are, while sealed in 
constant conditions, obtaining information about another well-known 
environmental daily rhythm, namely that of high-energy background 
radiation. This is so penetrating that it pervades all ordinary build- 
ings and containers. This radiation is highest about 6 in the morning 
and lowest between noon and 6 p.m. The daily range, or cycle ampli- 
tude, in the radiation, though averaging about 2 percent, varies greatly 
and unpredictably from day to day. The potato cycles also show 
variable total range, or amplitudes, from day to day. But the 
amplitude of the potato cycles on a given day is very clearly related 
to the amplitude of the background radiation cycle the day before. 
The greater the fluctuation in radiation yesterday, the greater the 
fluctuation in metabolism today. 
The potato sealed in constant conditions also obtains information 
as to the outdoor air temperature. As clearly seen in figure 6, the 
higher the outdoor temperature up to about 57° F., the higher the 
amplitude of the daily metabolic fluctuations. This relationship is 
reversed for higher temperatures. As everyone knows, there are 
clear daily and annual rhythms in air temperature. 
The potato in constant conditions also exhibited a lunar monthly 
rhythm of metabolism during a full-year period of study. As seen 
in figure 7A, the rate was lowest at the time of new moon and highest 
° 
o 
. 7, NOON DEVIATION 
0 10 20 30 40 50 60 70 80 
ATMOSPHERIC TEMPERATURE °F 
Ficure 6,—Relationship between percentage change in metabolic rate of potatoes between 
midnight and noon, and the outside air temperature. 
