2IO PHYSIOLOGY: H. SHAPLEY Proc. N. A. S. 
TABLE IV 
Frequency and Time of Day 
TIME OF DAY 
NUMBER OE 
OBSERVATIONS 
MEAN FREQUENCY 
In 
Out 
Ratio 
0 to 6 A.M. 
3 
0.87 
0.84 
1.04 
6 to 12 A.M. 
3 
0.45 
0.77 
0.58 
0 to 6 P.M. 
6 
1.22 
1.05 
1.16 
6 to 12 P.M. 
3 
1.11 
1.02 
1.09 
All 
15 
0.97 
0.94 
1.03* 
TABLE V 
Frequency and Temperature 
TEMPERATURE 
(Centigrade) 
NUMBER OP 
OBSERVATIONS 
MEAN FREQUENCY 
In 
Out 
Ratio 
14.5° to 22.5° 
8 
1.09 
0.94 
1.16 
22.5 to30.r 
3 
0.82 
0.96 
0.86 
30.5 to 38.5 
4 
0.84 
0.94 
0.90 
All 
15 
0.97 
0.94 
1.03* 
* If the terminal territories of different files do not overlap, this ratio in the long run 
should be unity or less. 
than out. In tables IV and V the quantity Ni/No is the ratio of average 
frequencies for the corresponding intervals of time or temperature; it 
has a different and better meaning than the average ratio of frequencies 
for the same intervals. 
The follov^^ing summary of conclusions may be based upon the tables 
and figure ; a discussion of the properties of the temperature-velocity curve 
s reserved for a later communication. 
1. From the measurement of the speed of a thousand individuals of the 
species Liometopum apiculatum, an empirical curve is. obtained that for 
any temperature throughout a range of 30 ° centigrade gives the speed with 
an average probable error of 5% for one observation. Conversely, from 
a single observation of the ant-speed, the temperature can be predicted 
within 1 degree centigrade. 
2. The activity is less erratic for higher temperatures. Thus, the 
percentage probable error, derived for each observation from the devia- 
tions of the individual timings, decreases on the average with increasing 
temperature and speed from about 4% to less than 2%; but for only one 
observation does the probable error exceed a millimeter a second. 
3. As the temperature rises 30° centigrade the speed changes fifteen 
fold, increasing uniformly from 0.44 to 6.60 centimeters a second. For 
a large species of Ectton, probably burchelli, observed by Beebe in British 
