(esse) 
| | | 
Males | Females 
| 
Cooled. Foreed. Cooled. Forced. 
| | 
«|, | Average |» | Average | Percentage || 1 Average | Average Percentage 
Family No.) expanse | No.) ‘expanse | Difference. expanse liane expanse Difference. 
I 6 3°93 2 3°88 1 IES; 7 411 4 3°89 on 
II D)| 8-84) Wave Bisuenie » 2078 3] 4:93 2 3°86 9°5 
aT MeO e-es eee as B47 | 10-4 9| 417 | 9 3°88 75 
IV |12| 387 | 4] 2345 | 122 | 17] 208 | 7 | 8:95 07 
10 | 3°77 8 3°32 13°6 | 14 8°85 | 4 3°80 i853 
| 
— ee i ! —— os l 
All 39 | 3°84 23 3°37 13°6 | 46 4:02 | 20 3°89 | 3:3 
“Treating all the families as one family, the results are as 
follows :— 
eee Se RS 
were Average wing | Increase of | Percentage | 
ey Description. expanse. ~ | the cooled, | of increase. 
39 Cooled males 3°84 \ 
eR Es eee ee : "47 13°9 | Males 
23 Forced males 3°37 J 
46 Cooled females 4°02 \ 
- ‘14 3°6 Females 
26 Forced females 3°88 J 
“Tt will be observed that in every one of the five families the 
cooled are, on the average, larger than the forced, the differ- 
ence ranging in the males from 1°3 to 20:8 per cent. (averaging 
13°6 or 13°9), in the females from 0-7 to 9:5 per cent. (averag- 
ing 3'3 or 36). It seems to me that the difference is too 
great and too diffused, embracing, as it does, each sex in five 
separate families, to be explained in any other way than this: 
that it is caused by something that, in consequence of the 
difference in temperature, happened to either those forced or 
those cooled, or both of them, in the pupal stage. ‘The only 
loophole I can see for error in this explanation is that the 
whole of the families were not preserved, some having been 
sacrificed for breeding purposes, so it may be that a larger 
proportion of those forced was preserved than of those cooled. 
The differences of aspect—colour, intensity, and to some ex- 
