34 AT A “HERONRY \ NEAR LONDON 
till they’ can) fly... The birds returngeach 
season to the same heronry, following the 
habits of rooks. In some cases the old birds 
rebuild their nests year after year, and so 
the structure gets larger and larger. (Men- 
tioning o/d birds, I do not know the exact 
longevity of herons—or, indeed, of any other 
bird, at all events not in the wild state. 
And why are no old herons or any other 
old birds or animals found dead? One 
rarely knows or hears of such a thing. 
The reason is doubtless that immediately a 
creature of any kind knows that it is going 
to die it retires into some hole or corner— 
and Nature has, moreover, provided that its 
carcass should not he to decay and be a 
source of annoyance by its odour—or cause 
disease by putrefying. It is, in fact, at once 
devoured. Field voles, shrews, rats, carrion 
crows and other scavengers immediately set 
about it, and what is not accomplished by 
these larger scavengers is completed by beetles 
and other insects. In summer ants will come 
and leave the bones bare, and all the time 
