110 
ever, have their peculiar protection in the hairy pap- 
pus or down which first guards the infant progeny 
to the full period of maturation, and then wafts 
them through the air, for the purpose of extensive 
distribution. 
Nidification. 
In noticing the care of offspring, I have already 
remarked that some animals of every class exhibit 
more and some less care in providing for their future 
progeny, by the construction of warm and conveni- 
ent nests. 
Among mammalia, those with hoofs, and with 
pads, as the elephant, &c. equally unfit for manufac- 
turing purposes with hoofs, are bad nest-makers : 
while those, whose claws are scarcely less fitted for 
diversity of operation than the human hand, almost 
rival man in the construction of bridges and super- 
aqueous habitations, and may enter into competition 
with birds as nest-makers. 
The wonderful edifices effected by the combined 
exertions and ingenuity, or yet more inexplicable 
instinct of beavers, are too familiarly known to all 
who have ever looked into the most common histo- 
ries of animals to need repetition of description. 
The nests of squirrels, of marmots, of rats, especially 
the hamsters, of field-mice and dormice, resemble 
and rival those of birds. The larger birds of prey, 
and the largest and strongest of the insectivorous, 
or rather of the mixtivorous, employ coarse mate- 
rials, and build loosely-compacted nests. The mag- 
