158 
GREENLAND VOYAGE. 
pores of the hardest wood; yet it is effectually re¬ 
sisted by the skin of the whale, though it is re¬ 
markably soft and flexible. To exclude the water 
from the lungs, which would occasion suffocation, 
if admitted, the blowholes are defended by the pe¬ 
culiar valves that have been already described. 
The variety discovered in the structure of the 
valves of the blowholes of whales, is by no means 
one of the least interesting parts of their pliysio- 
logy. In other classes of animals, whose habits 
arc similar, we often find, that each organ is the 
same as the corresponding one, in almost all the 
species of the same genus, or even of the same or¬ 
der ; excepting when their peculiar habits, or ne¬ 
cessities, require a modification of the general 
structure or principle. But in whales, as if it 
were intended, not only to exhibit the matchless 
wisdom of the Creator, but, to show that his re¬ 
sources are unlimited, the structure of the breath¬ 
ing canals is varied in the different genera of ce¬ 
taceous animals, and a number of contrivances, 
alike extraordinary, equally beautiful, and equally 
efficient, are adopted for performing the same of¬ 
fice. 
In the afternoon of the 15th, the continuance 
of the fog preventing our cruising in search of 
whales, we made the sliip fast to a heavy lump of 
ice, for the purpose of repairing the damage sus- 
