THE PROCESSIONARY CATERPILLAR 31 



The migration of Processionary Caterpillars, 



which is typical of all migrations, the purport 



being food, offers exceptional opportimities 



for test experiments. 



Let the observer try the effect of transpos- 

 ing the units of the column : Place (say) the 

 leader at the end and put the last caterpillar 

 at the head of the procession, and then watch 

 results. It will be found that when the dis- 

 turbance has subsided (this may take some 

 time) the march will continue as if nothing 

 had happened. Here it may be recommended, 

 that if found necessary to handle the cater- 

 pillars, old gloves should be worn to be after- 

 wards thrown away, for these larvae bear an 

 armature of urticating hairs of a dangerous 

 nature, a protection, however, of great service 

 to them when thus travelling in the open. 



