472 
SUPPLEMENT 
middle of May, and particularly in tlie morning of those days 
in which the weather is disposed to be stormy. The two 
sexes cover themselves with a thin and very delicate tissue, 
which they construct in common. The male, after having 
spread some threads on that side of the tent where the female 
is placed, advances towards her, touches her gently a minute 
or two on the back, and finally determines her to quit the 
motionless and contracted posture which she held. After 
this the coupling takes place. When the amours of these 
animals are terminated, the two sexes live together in tran- 
quillity, forming, in this respect, a rare exception in the 
spider race. This good understanding appears to be general 
among all the Theridia. 
Of all the known theridia, the species most deserving of 
our attention is that which Rossi calls 13 -guttata, and 
which is the spider known in the island of Corsica, under the 
name marmignatlo , or marmagnato. According to him its 
bite is mortal, even to man himself. It produces the most 
serious symptoms, which scarcely disappear by the operation 
of sudorifics and scarifications. This animal spreads along 
the furrows of the fields different threads, so as to stop or 
impede the progress of locusts, of which it makes its prey. 
Having the body reversed, and suspended by the fore-feet, it 
draws, by the help ot the hinder feet, some new threads, 
which it shoots very quick, and by an undulatory movement, 
on the feet of the locust, until it has sufficiently entangled it 
to approach without any fear. It first bites it near the neck, 
and then sucks it at its leisure, as the animal, on being bitten, 
falls into a convulsion immediately, and perishes. If enclosed 
in a vessel with a locust, the thcridion, by trying to envelope 
it, soon exhausts all its silky matter and dies itself, having 
lost all its strength. It will not attack the European scorpion, 
or different spiders which may share its captivity ; but it is 
not so with individuals of its own species, with which it 
