118 A JOURNEY IN BRAZIL. 
his cocoon on the leaf. We watched him for a long time 
with the lens as he wove his filmy tent. He had 
arched the threads upwards in the centre, so as to leave a 
little hollow space into which he could withdraw ; this tiny 
vault seemed to be completed at the moment we saw him, 
and he was drawing threads forward and fastening them at 
a short distance beyond, thus lashing his house to the leaf 
as it were. The exquisite accuracy of the work was 
amazing. He was spinning the thread with his mouth, 
and with every new stitch he turned his body backward, 
attached his thread to the same spot, then drew it forward 
and fastened it exactly on a line with the last, with a 
precision and rapidity that machinery could hardly imitate. 
It is a curious question how far this perfection of workman- 
ship in many of the lower animals is simply identical with 
their organization, and therefore to be considered a function, 
as inevitable in its action as digestion or respiration, rather 
than an instinct. In this case the body of the little animal 
was his measure : it was amazing to see him lay down his 
threads with such accuracy, till one remembered that he 
could not make them longer or shorter ; for, starting from 
the centre of his house, and stretching his body its full 
length, they must always reach the same point. The same 
is true of the so-called mathematics of the bee. The bees 
stand as close as they can together in their hive for 
economy of space, and each one deposits his wax around 
him, his own form and size being the mould for the 
cells, the regularity of which when completed excites so 
much wonder and admiration. The mathematical secret 
of the bee is to be found in his structure, not in his 
instinct. But in the industrial work of some of the 
lower animals, the ant for instance, there is a power of 
