THE PROTECTION OF BIRDS. 409 
ful Birds,” in which he gives a method of protecting their 
nests from their enemies. Of sixty-seven nests observed 
from April to August, only twenty-six prospered. Of the 
forty-one destroyed, fifteen were known to have been robbed 
by cats, eight by the garden dormouse, three by Jays, and 
two by Magpies. He protected twenty nests either by fur- 
nishing the birds vermin-proof bird boxes to build in, or 
by surrounding the nests with wire netting. Only two of 
these were robbed of eggs or young, and they were pillaged 
by animals that got through or under the netting. These 
simple methods of protection assured the rearing of one hun- 
dred and two young birds from nineteen nests. Comparing 
these figures with those from the unprotected nests, we find 
that, proportionately, only seven pairs of parents out of the 
twenty would have succeeded in rearing their young had 
their homes been unprotected. The paper lacks a complete 
description of the method of putting up the wire nest pro- 
tectors. There is nothing to show whether the enclosure was 
without a cover, or whether an opening was left in the top 
just large enough to admit the parent birds; but the mesh 
used was, in some cases at least, small enough to keep out 
mice, or about one-fifth to one-sixth of an inch in diameter. 
The language used seems to indicate that the nests on the 
ground were merely enclosed by a circular fence of wire 
netting. Mons. Raspail says that nests so protected are not 
attacked by weasels or mice. There seems to be nothing 
to prevent these animals from climbing over the wire, except 
that they may stupidly strive to get at the nest from below, 
and so walk around the cage without seeking an entrance 
above. The sly fox, perceiving the smell of iron, might sus- 
pect a trap. Probably Crows and Jays, being also suspicious 
of a trap, would not enter these enclosures. The surround- 
ing of the nests with netting in no case caused the birds to 
desert their home, even when it was done as soon as the nest 
was completed and before the eges were laid. This method 
might be worth a trial. 
Where nesting trees are isolated, cats and squirrels may 
be kept out of them by the use of either of the devices shown 
‘in the cut (Fig. 171), for these animals cannot climb up a per- 
