1825. 
For the Monthly Magazine. 
Extracts from a Manoscrirr Tour 
in the Soutu of France. 
HILE scrambling over one of 
the arid heights of Provence, 
my attention was attracted by the 
manceuyres of a troop of emigrating 
insects. It is easy to attribute the sin- 
gular. economy of the insect world to 
the mere influence of instinct; but we 
may readily lavish our admiration on 
the wonderful arrangements of some 
tribes, whose operations may be more 
particularly exposed to our scrutiny: 
and this may, surely, arise more from 
our deficiency of observation and op- 
portunity, than from the inferiority of 
one class to another in the marvellous 
nature of ‘their operations. .Whenever 
our observations penetrate into the wide 
field of nature, cause for wonder will not 
be wanting,,or motives for diffidence in 
the limited extent of our own faculties. 
It is admitted that instinct may account 
for such a proceeding as long as no op- 
position interrupts; but what must we 
call that species of intelligence which 
instantly proceeds to search for prac- 
ticable remedy of such interruption ? 
I observed, what appeared to me, a 
very slender snake, writhing across my 
path, which, but for the unusual season 
for these animals to appear, I should, 
no doubt, have passed unheeded. Upon 
examination, however, it turned out to 
be an orderly emigration of large cater 
pillars, assiduously proceeding along 
the rocky tortuous path, in a line of 
march by single files, and so close, that 
each seemed to cling to his neighbour’s 
tail. The steep and irregular surface 
of the path rendered their progress very 
difficult, and much interrupted by op- 
posing stones, over the tops of which 
they were generally more inclined to 
pass than round their bases; while the 
frequent recurrence of such impedi- 
ments formed a continued wave in their 
motion, which had a very singular ef- 
fect. The line of march, however, was 
unbroken—no troops could mark time 
with greater precision or patience than 
did the rear of the line, while the front 
was climbing over any obstacle, or the 
leader stopping to examine any diffi- 
culty; the front, in turn, tarrying until 
the rear surmounted the impediment 
it had just overcome. They were twenty- 
two in number, and all nearly of the same 
size, except one, whose place was in the 
centre of the line. The leader, on the 
contrary, was somewhat smaller than the 
rest. A large precipitousstone lay in their 
Migration of Caterpillars. 
229 
way; the leader reared up, and, moving 
his head from side to side, seemed 
examining it, and, as it were, willing to 
reach some corner or roughness where- 
by to ascend; but not succeeding, he 
led his troop round and round, repeat- 
ing the examination, until they reached 
a small bush, up the stem of which they 
ascended “ in order due,” the long line 
following with perfect confidence ; and 
then by means of a branch of the bush, 
they obtained, footing on the stone: 
traversing the stone, the further side of 
which was quite precipitous and pretty 
high, it became uncommonly interest- 
ing to see how this intelligent general 
would proceed. He examined it with 
accuracy, trying every possible break ; 
during which time the main body re- 
mained patiently waiting, not making 
the slightest attempt to assist in- the 
examination, which their leader con- 
ducted with much activity and solici- 
tude. At length, having ascertained 
the pass to be quite impracticable, he 
resolved upon a counter-march, which 
was instantly performed with the most 
surprising regularity. For the whole 
line, in succession, advanced to the 
wheeling point, on the brink, before they 
turned, which they then effected with 
as much precision as the best trained 
troops could have done; the advancing: 
and retreating lines passing close, climb- 
ing the same twig in opposite direc- 
tions, and occasionally passing over 
each other’s bodies, without the least 
confusion or hesitation. Having com~ 
pleted their descent, a new line of di- 
rection was taken, which was, however, 
soon alarmingly interrupted by the ar- 
rival of a woman, leading an ass laden 
with brush-wood, some branches of 
which trailed along the path. After 
the passage of this formidable assailant 
I returned, with some anxiety, to exa- 
mine the state of the colonists, and 
found that they had suffered materially. 
from the disaster, and were thrown into 
grievous disorder. The line had been 
broken, but a considerable body still 
followed the leader with a quickened 
pace: others, united in parties of three 
or four, regularly kept their positidn in 
rear of one another, while the tempo- 
rary conductor sought, with manifest 
trepidation, to rejoin their tried and 
chosen leader and the main body, from 
which they had been so suddenly and 
so unfortunately separated, hastening, 
with apparent alarm, first to one side, 
then another; others were scattered 
singly, and, in much distress, seemed 
quite 
