246 DR SUTHERLAND SIMPSON ON 
in Ithaca, when they were resumed again for four consecutive days till 6 am. on 
September 14. On September 12 and 26 and October 3 the three twenty-four 
hour periods were spent at rest in bed, as on the former occasions in Winnipeg and 
Scotland. On September 12 and October 3 the three ordinary meals were taken, 
but on September 26 food was abstained from (see Table I1.). 
IV. Resutts anp Discussion. 
The results of this continuous series of observations from June 19 till September 14, 
with the interruptions as indicated, are presented in the accompanying temperature 
charts (figs. 1 to 5). The thick continuous line represents the rectal temperature, the 
dotted line the mouth temperature, and the thin continuous line, usually the lowest in 
position, the axillary temperature. The division of the twenty-four hours into night 
and day periods is indicated graphically by the alternate light (6 a.m. to 6 p.m.) and 
dark (6 p.m. to 6 a.m.) bands at the bottom of the chart according to Ithaca local time. — 
The hatched and intermediate clear seoments extending through the whole width of 
the chart shows night (6 p.m. to 6 a.m.) and day (6 a.m. to 6 p.m.) by ship and train 
local time, and the alternate light and dark bands at the top the same by Edinburgh — 
time. This division is somewhat arbitrary, since from June 19 till September 21 the 
sun rises before and sets after 6 o'clock, so that the dark and hatched bands on the 
chart are more extensive than the natural night period, but the attempt to construct a j 
chart in which these should coincide exactly with the dark periods for the different — 
latitudes in which the observations were made was found to involve too much labour 
and was abandoned. In the Orkneys a newspaper could be read outside the house at 
10 p.m. and again at 2 am., the actual dark period at that season of the year being of 
very short duration. As it stands this feature of the chart is only meant to show in a 
graphic way the relative differences between the local time on the journey and that of 
Ithaca and Edinburgh. From June 19 to 25 it will be observed that the dark and 
hatched bands coincide, and also from September 10 to 14; but on the voyage east- 
ward the ship’s local time moves forward, and on the voyage westward it moves back- 
ward in relation to Ithaca time. 
The figures at the left side of the chart represent degrees centigrade, those at the 
bottom hours of the day, and those at the top days of the month. Twelve o'clock 
noon occurs at the middle of the clear band and 12 o'clock midnight at the middle of 
the hatched band, each space between the vertical lines representing an interval of 
three hours. 7 
A careful scrutiny of this chart will bring to light some interesting facts, and the 
first and most obvious of these is that the body-temperature curves of no two days are 
alike. If inherent rhythmicity were a predominant feature, one would expect to find 
a closer resemblance between the curves on different days, whereas they all seem to 
be controlled to a very large extent by the conditions imposed on the body. ‘This is 
