1914] Longevity of Insects 333 
Between 64°F. and 58°F. there must be a temperature with 
another characteristic for 64°F. holds a transitory position in 
that it gives an increase in longevity when followed by a low 
temperature and a decrease in longevity when followed by a 
high temperature. 
“Low” 58-46°F. 
These temperatures show the characteristics ascribed to 
“‘Low Temperatures.” 
Since death by starvation is the end of the phase we are 
studying in this experiment, it was thought that probably a 
measure of the rate of growth would determine this rate of 
senescence. Sanderson recommends the following method of 
obtaining a temperature growth curve, viz: that a ‘“‘definite 
valuation’”’ be found “‘in relation to the accumulation of temper- 
ature necessary for any stage of growth” in the following 
manner: if, at a certain temperature, it requires x days to go 
through certain phases and this development be considered 
equal to one unit, then each day’s growth at this temperature 
is equal to (1l+x)%. Using this method, the following tabu- 
lated growth valuations were found: 
Table 5. Temperature Growth Valuations per Day. 











Growth E | | Growth Growth 
Exp.|No. Days) Temp. Value No. Days Temp. | Value Value 
Ist.Temp Ist Temp. [24d Temp. 2nd Temp. | Total 
A 9 | High a 9 5 2a bce] a pons Dare ee 1.0 
9 Me Reln te | wreMeO PON more, Slere tk eats. De ge A eae AE 1.0 
38 Low HO ZS EXM OOP ae ected tes pea seed ae Sete Soc ree 1.0 
2 Med. 222 5.3 | High 147 1.0 
2 Med. 222 33.1 | Low .0235 1.0 
2 | High 229 7.2 | Med 108 1.0 
2 | High . 222 36 Low .0216 1.0 
2 | Low .052 ioe) ashe 4) .0837 1.0 
2 | Low | .052 12 | Med. .079 1.0 
B POU etsy ee OGG) yes. bse [ace eee fees eee ses 1.0 
13.4 | Med. ALEC) Sc: SIU oe |e Me a 1.0 
22 Low Ra ee fegee eM en ee eS rca wae a [a asenPyaval ov bm eae XO 
2 Med. | .1492 24.5 | Low .0347 1.0 
2 Med. ~}..1492 13.6 High .0625 | 1.0 
a | High | .1204 ee ae Med. 0733) EO 
2 | Low — .0908 i -ia.2 | Med. .0689 | 1.0 
2 | Low 0908 | 27.8 | High 0323/5 «5250 


