60 ROBERT STANLEY McEWEN 
such conditions, though I have not infrequently had them live 
longer. For some reason not recorded no B and C groups of 
males were started. Hence this experiment is not particularly 
satisfactory. However, so far as it goes it tends to uphold the 
views already stated. The males gain on the females as age in- 
creases, and both sexes show a general increase up to the time 
when feeding was necessary. The results are summarized in 
table 3 and the accompanying graph. 
There remain to be described a couple of experiments which 
throw more light on the fatiguing effect of frequent tests given 
TABLE 2 
Males 
MReEMpPOLrahuUTrescecirceaeiees 22° 20° PAL as> PB) 24° 24.1° 2am | 24° | Zao 
Hours Days 
Age in hours or days.... 4 12 15 18 21 24 2 3 4 
Group 
MNS Sa ome ee a S220) | 6025s | oreo) | G2E0N G9n5n (225al 7120) S4a0n esan0 
BE ie Sekt a a le 1356) |). || So. |) ED |) ea) ESA) |) EO) | Silt |) 77/6 
Cees i ee 83.5 | 51.5 | 62.5 | 63.0 | 87.5 | 89.5 | 95.0 | 96.0 | 92.0 
INGEN ood cose oa) Wash |) Doll SOs ic PRS NPC as || GG G8 I Sil || SALI 
Temperature..... 21208 | 21.6° 23254 24.6° 22.8° PAB? 22.5° 20.0° 23.0° 24.5° 
Days 
Age in days..... 5 6 7 8 9 10 11 12 131 14 
Group: 
Wonsdsovecsl| Gedy | 7sei | GO Freer 73.7) |) ea | RB ere | Sil || 333.0 
Bee eeeee | olieos|) COLON al SOM GS251 Gos on MOOR On ROMO Ni n4 450m aoe om mom) 
Cree ea) Soe 0) Oe al OIA 07 89054 eS220N TS >xOMeSseon (OL onl Slm On msone 
Average...... 79.6 | 81.9 | 76.2 181.9 | 73.5") 72.0 | 64.4 | 56-8 | 7325) a 26 
1On this day one fly from the A group of males was lost. As the records 
indicate that very probably the fly lost was a slow one, a new calculation was 
made on the assumption that had this fly been present it would always have 
remained in the zero section. The figures resulting from this calculation are 
72.1 for the thirteenth day and 73.8 for the fourteenth. This changes the aver- 
ages for these days to 70.5 and 69.6 respectively. 
