ON THE MARCH 31 



as I could estimate the number, there were about 

 two or three thousand big ants, and all were formed 

 into 'fours,' though in military phrase the 'fours' 

 did not keep their * dressing.' The outside members 

 of each ' four ' never moved from their position, but 

 the insiders constantly kept changing places across 

 the column. They moved along like a huge black 

 snake, and were led by a single ant, who examined 

 the ground like a scout, while the column implicitly 

 followed his movements, and apparently his direc- 

 tions." Four times Mr. Millais picked up and threw 

 away the leader, and thrice another came forward to 

 take its place, when the army, which had halted, 

 resumed its march. 



Commissariat, the curse of armies on the march, 

 presents few difficulties even to vast moving bodies 

 of animals when wild. Almost the only creatures 

 which are noticed to suffer from hunger in these 

 journeys are the migrating lemmings and, as men- 

 tioned above, the rear columns of the spring-bucks. 

 This is because the travelling animals are all vege- 

 table feeders, and move as a rule in the direction of 

 an increased food-supply the musk-oxen travelling 

 south in winter, and north when the Arctic summer 

 uncovers the tundra, and the animals of the veldt 

 or prairie advancing or retiring over their feeding- 

 grounds when plenty follows rain or scarcity follows 

 snow. Where this natural commissariat is not avail- 

 able, Nature has to overcome the difficulty by very 

 specialised means. Many birds feed up for days 

 before the effort of the over-sea migration flight, and 



