8o 



The Study of Animal Life 



tancc, produce an effect resembling the flashing of the 

 Aurora BoreaHs ; sometimes the effect is that of rainbow 

 hues in the spray of laughing waterfalls ; sometimes that of 

 fire ; sometimes that of a smoke-wreath." " Each column 

 looks like a kind of slender network, and has a tremulous 

 undulating motion. The noise emitted by myriads and 

 myriads of these creatures does not exceed the hum of 

 a single wasp. The slightest zephyr disperses them." 

 After this midsummer day's delight of love, death awaits 

 many, and sometimes most. The males are at best short- 

 lived but the survivmg queens settlm^, down, miv bet, n 



r 17 — Si ba ants it work to the left below an or 1 na y worker t tl c 

 right a large headed worker , above, a subtenanean worker. (From L.itcs.) 



to form nests, gathering a troop of workers, or sometimes 

 proceeding alone to found a colony. 



A caste of workers (i.e. normally non- reproductive 

 females) distinct from the males and queens, involves, of 

 course, some division of labour ; but there is more than 

 this. Workers of different ages perform different tasks — 

 foraging or housekeeping, fighting or nursing, as the case 

 may be ; and just as the various human occupations leave 

 marks both for g"Ood and ill in those who follow them, so 

 the division of labour among ants is associated with differ- 

 ences of structure. Thus, in the Saiiba or Umbrella Ant of 

 Brazil (CEiodoina ccphulofcs), so well described by Bates in 



