LONGEVITY IN SATURNIID MOTHS 189 
Another interesting feature was the degree of pigmentation 
displayed by these insects. While no measurement was made of 
the color or its distribution, the general darkness of this lot was 
clearly evident. 
Out of the 162 insects which emerged from the incubator lot, 
records were kept on the duration of life of 112. The mean length 
of life for this lot compares well (table 1) with the results from 
the New York and St. Louis 1911 material. The following table 
gives the details of the duration of life of this lot. 
TABLE 5 
Incubator Cecropias 
DAYS 
CLASS it aes l (ldenat a oe ; | T. |MEan 
£9) 05 WIG NE 68) 9 | 20H) Lie) 12 esa as le 
| | } 
Metiedeis Se... hid caay st eee et |! Bh oc RG 4 20 | 8.10 
Whamiated UB: ca2// 3 bnes yose cowie eden ee) ie alee Uy ines es Wee oe 39 | 8.31 
Werpeclk Ons ee een fee nee ee ecg (Pty; Sul Os| ye Our 2418 Fe ihe eB ees 
fn ated yQ.'S- waste onc bones vie a [Norte asa a5 2} 1] 2) 4 | | 20 | 8.80 
Allimated imsewpsi....2.<- 628. -5--%-| 1 5/1318) ACTEM RT at | | | 53 | 7.40 
All unmated insects.................. | 4| 5] 8/44) is] 6) #] 4) a) | | 59 | 8.48 
NU a eee | 5 T| 8/12/14) 4] 7) 2| | | | 59 | 8.24 
INI 69, cereal ear ee be eae re ected bata t/a [as 5/13] 2] 1] 2] PT SES ania 
Misuleipopulationy: co... --.4e.chn- 4) 2) 9) U8 20 17 [27 Co) ae a | 112 | 8.00 
| 
| 
| 
| 
ICE-BOX MATERIAL, CECROPIA 1911 
Finding it impossible to get the incubator material to emerge 
during the winter, and wishing to ascertain definitely whether 
the duration of life is influenced by low temperature, a number of 
cages containing two insects each were placed in an ordinary 
household ice-box, the temperature of which varied from 9° to 12° 
C., and on a few occasions 15°. Forty-two insects were used in 
this experiment, and the duration of life varied from 6 to 32 days. 
Had the temperature been uniform in all parts of the ice-box, 
the 18 insects which lived 13 days or less would probably have 
lived longer. As it was, most of those which were kept on the 
top shelf nearest the ice compartment lived the longest. Corre- 
lation table 7 shows that their contemporaries lived the normal 
number of days. 
Lack of facilities and material made it impossible to make 
more extended observations. This number, however, gives suf- 
