268 CATERPILLARS AND THEIR MOTHS 



the third or fourth caterpillar would feel the thread 

 with only one palpus and so walk along at one side 

 of it, spinning his own thread parallel to it ; then the 

 next larvae would find two threads, and the procession 

 would march by twos. Sometimes other caterpillars 

 still farther back would follow at the side of, instead 

 of on, the threads spun, and their parallel threads 

 would widen the ranks still more, until it was a wedge- 

 shaped mass. In any case it was a funny sight to see 

 these small caterpillars following a leader along stems 

 and leaves to feed, and back again to rest. We could 

 not make out whether it was always the same leader, 

 or how the leader started his followers. There 

 seemed to be no communication between them, and 

 unless the vibration of the leaf or stem, when the 

 leader started, aroused the others, we could see no 

 way of doing it. 



For eight days they marched and fed, then molted, 

 and were just as before, but larger. 



They fed and marched, and rested in rows for 

 two weeks more, then molted again. This time their 

 heads were black, their bodies brown, with a sublat- 

 eral band of lighter brown edged with white lines. 

 The spines were black and dense, the legs dark, the 

 props light brown. Toward the end of this stage they 

 began to scatter over the leaves and stopped marching. 



In seven days they molted, coming out pale green 

 all over, except the brown and white sublateral stripes, 

 and a few black spines among the green ones. 



Eight days later they molted for the fourth time, 

 and were pale green, with the brown and white sub- 

 lateral bands, a substigmatal line of brown patches, 



