HOUSE-MARTINS. 197 
I injured by them as by many species of coleoptera (scarabs), and 
j tipuloi (long-legs), in their larva, or grub-state ; and by unnoticed 
I myriads of small shell-less snails, called slugs, which silently and 
imperceptibly make amazing havoc in the field and garden.* 
These hints we think proper to throw out in order to set the 
inquisitive and discerning to work. 
A good monography of v/orms would afford much entertain- 
ment and information air the same time, and would open a large 
and new field in natural history. Worms work most in the 
spring ; but by no means lie torpid in the dead months ; are out 
every mild night in the winter, as any person may be convinced 
that will take the pains to examine his grass-plots with a candle; 
are hermaphrodites, and much addicted to venery, and conse- 
quently very prolific. I am, &c. 
LETTER XXXVI. To the Hon. DAINES BARRINGTON. 
DEAR SIR, Selborne, Nov. 22, 1777. 
You cannot but remember that the twenty-sixth and twenty- 
seventh of last March were very hot days ; so sultry that every 
body complained and were restless under those sensations to 
which they had not been reconciled by gradual approaches. 
This sudden summer-like heat was attended by many summer 
coincidences ; for on those two days the thermometer rose to 
sixty-six in the shade ; many species of insects revived and came 
forth; some bees swarmed in this neighbourhood; the old 
tortoise, near Lewes in Sussex, awakened and came forth out of 
its dormitory ; and, what is most to my present purpose, many 
house-swallows appeared and were very alert in many places, and 
particularly at Cobham, in Surrey. 
But as that short warm period was succeeded as well as pre- 
ceded by harsh severe weather, with frequent frosts and ice, and 
cutting winds, the insects withdrew, the tortoise retired again 
into the ground, and the swallows were seen no more until the 
tenth of April, when, the rigour of the spring abating, a softer 
season began to prevail. 
Again ; it appears by my journals for many years past, that 
* Farmer Young, of Norton-farm, says that this spring (17/7) about four acres of hi* wheat in 
one field was entirely destroyed by slugs, which swarmed on 'the blades of corn, and devoured it 
as fast as it sprang, 
