INSECT AND OTHER STRATEGISTS 107 



not less singular than effective. Placing itself in the inside of the 

 circle which it has traced, it thrusts the hindpart of its body under the 

 sand and with one of its forelegs serving as a shovel, it charges its flat 

 and square head with a load, \vhich it immediately throws over the 

 outside of the circle with a jerk strong enough to carry it to the dis- 

 tance of several inches. This little manoeuvre is executed with sur- 

 prising promptitude and address. A gardener does not operate so 

 quickly or so well with his spade and his foot, as the ant lion with its 

 head and leg. Walking backwards and constantly repeating the proc- 

 ess, it soon arrives at the part of the circle from which it set out. It 

 then traces a new one, excavates another furrow in a similar manner, 

 and by a repetition of these operations, at length arrives at the center 

 of its cavity. One circumstance deserves remark that it never loads 

 its head with the sand lying on the outside of the circle, though it 

 would be as easy to do this with the outer leg, as to remove the sand 

 within the circle by the inner leg. But it knows that it is the sand in 

 the interior of the circle only that is to be excavated, and it therefore 

 constantly uses the leg next to the center. It will readily occur, how- 

 ever, that to use one leg as a shovel exclusively throughout the whole 

 of such a toilsome operation, would be extremely wearisome and pain- 

 ful. For this difficulty our ingenious pioneer has a resource. After 

 finishing the excavation of one circular furrow, it traces the next in an 

 opposite direction; and thus alternately exercises each of its legs 

 without tiring either!" 



There is one other insect, a Caddice worm, 1 well worthy of a place 

 among these instinctive strategists. This creature lives under the 

 water. It is a true fisherman in every sense of the word, for it catches 

 its food by constructing a silken net in the current of the stream which 

 it inhabits. The mesh of this net is almost perfect in its symmetry, 

 each strand of silk being fastened at a right angle with the one next 



1 Hydropsychidae. 



