INTELLIGENCE OF LARVJ2 CATERPILLAKS. 239 



600 or 800 individuals. When young they have no fixed habi- 

 tation, but encamp sometimes in one place, and sometimes in 

 another, under the shelter of their web ; but when they have 

 attained two-thirds of their growth, they weave for themselves 

 a common tent. About sunset the regiment leaves its quarters. 

 . . . At their head is a chief, by whose movements their pro- 

 cession is regulated. When he stops all stop, and proceed when 

 he proceeds; three or four of his immediate followers succeed 

 in the same line, the head of the second touching the tail of the 

 first ; then comes an equal series of pairs, next of threes, and so 

 on, as far as fifteen or twenty. The whole procession moves 

 regularly on with an even pace, each file treading in the steps 

 of those that precede it. If the leader, arriving at a particular 

 point, pursues a different direction, all inarch to that point 

 before they turn. l 



The following additional facts concerning these remark- 

 able habits may be quoted. I take them from the ac- 

 count published by Mr. Davis in 'Loudoun's Magazine of 

 Natural History : ' 



The caterpillars, he observed, were Bombyces, and were 

 seen crossing a road in single file, each so close to its predecessor 

 that the line was quite continuous, ' moving like a living cord.' 

 The number of caterpillars was 154, and the length of the line 

 27 feet. When Mr. Davis removed one from the line the 

 caterpillar immediately in front suddenly stood still, then the 

 next, and next, and so on to the leader. Similarly, those behind 

 the point of interruption successively halted. After a pause of 

 a few moments, the first caterpillar behind the break in the 

 line endeavoured to fill up the vacant space, and so recover con- 

 tact or communication, which after a time it succeeded in doing, 

 when the information that the line was again closed was 

 passed forward in some way from caterpillar to caterpillar till 

 it reached the leader, when the whole line was again put in 

 motion. The individual which had been abstracted remained 

 rolled up and motionless ; but on being placed near the moving 

 column it immediately unrolled, and made every attempt to get 

 readmitted into the procession. After many endeavours it 

 succeeded, the one below falling into the rear of the interloper. 

 On repeating the experiment by removing a caterpillar fifty from 

 the head of the procession, Mr. Davis found that it took just 

 thirty seconds by his watch for information of the fact to reach 

 the leader. All the same results followed as in the previous 



1 Kirby and Spence, Eitomologi', Letter xvi. 



