NATURE’S MEANS OF LIMITING THE NUMBERS OF INSECTS. 277 
do not reveal themselves to the eye of the bird, which perceives 
more easily and follows more willingly the insects which fly or 
in homes of 
persevering care, cannot even in a small farm, rid himself of them, 
nor often even free his house of them, not even a portion of i 
. ‘‘The grubs and caterpillars, which are more especially the au- 
thors of the damages, live almost T concealed under the soil, 
under bark, deep in the road, in the stems of plants, in fruits, in 
- inhabited placės, under silken nets, asd only pay the birds a very 
feeble tribute. Those which are developed in the open air are 
generally hairy, which repels birds ; certain of them are noctur 
and ae tine before day ; others are protected by their excessive 
smallne 
a, in another place enumerates other useful animals, and his 
remarks will apply in the main to this country :— 
“There are among the mammalia, the moles, which without 
afais do some mischief in covering our fields with mole hills 
. but they benefit us by destroying many insects and injurious 
Be nocturnal.” 
He also enumerates certain birds, and the larger number of the 
reptiles, adders, the blind worm, lizards, frogs, rennets, toad and . 
urtle. The toads are of especial value as their only diet appears 
to be flies and grasshoppers and other insects. These animals are 
extremely sedentary. Wherever they find a supply of insects 
there they will remain for weeks at a time, as long as the supply 
lasts. On Penikese island, some of the students of the Anderson 
School of Natural History discovered that the stomachs of the num- 
erous toads there were filled with young grasshoppers, and that 
- they even hopped down to the shore and fed upon the beach-fleas 
which live under sea-weed between tide-marks. Toads are doubt- 
less of use in devouring canker worms, as they abound under apple 
trees infested by them, and probably devour large quantities when 
the worms descend in June to the earth in order to undergo their 
transformation into the chrysalid state. It would ‘be worth while 
to collect them in large numbers and place them in gardens and 
orchards, as once deposited there, they will remain. 
Before I leave this subject of the agency of birds and other 
vertebrate animals in maintaining this equilibrium in the numbers 
