102 OF SOCIABLE CATERPILLARS. 



" I obsen'ed," says he, " what appeared to me 

 a very slender snake writhing across my path, which, 

 but for the unusual season for these reptiles to ap- 

 pear, should no doubt have passed unheeded. Upon 

 examination, however, it turned out to be the orderly 

 emigration of a colony of large catci-pillars. They 

 were proceeding assiduously along the rocky path, 

 in a line of march by single files, and so close, that 

 they appeared to have a hold each of his neighbour's 

 tail, and the continued wave formed by their motion 

 had a very singular effect. The stony surface of the 

 path rendered their progress exceedingly tortuous, 

 and inteiTupted by much climbing over stones, as 

 they seemed in general more disposed to go over 

 the top of a stone than round its base. When such 

 obstacles occurred, the march, notwithstanding, did 

 not sustain the slightest derangement, as no troops 

 could mark time with greater precision and patience 

 than the rear of the line, while the front was en- 

 gaged in climbing over any obstacle, or the leader 

 had stopped to examine the difficulty ; the front, in 

 their turn, tarrying until the rear had succeeded in 

 surmounting the obstruction which the front had 

 just passed. They were twenty-two in number, 

 and nearly of the same size, except one, considerably 

 larger than the rest, whose place was exactly in the 

 centre of the line. The leader, on the contrary, 

 was rather smaller than any of the rest. A large 

 precipitous stone was in their way; the leader 



