70 Observation.^ on the Habitft of Certain Flies 



the tubes were empty their outer ends were closed with rubber corks. 

 In this way temperatures were taken daily at several points in the heap 



Fig. 3. 



Fig. 4. 



Ficfs. 3, 4. A, balloon trap: 7?, woodonsquarc witli hole in centre to hold trap: C, lid of 

 tobacco tin (wit.li hole in centre) to catch muslin: D, square wooden box: E, muslin, 

 soaked in black ink caught under tobacco tin and at sides of box: F, roof to shelter 

 thermometers: G. wooden wall against which manure was placed: //. support wires: 

 I, mushn: J, latli. holding muslin: K. outside of tray containing sawdust (Figs. 1.2): 

 M, manure. 



without disturbing; the manure. The thermometer was left in each tube 

 for 10 mins. — the temperature becoming constant in that time. 



