8 TRANSACTIONS—PERTHSHIRE SOCIETY OF NATURAL SCIENCE. 
wound inflicted by our common back-swimmer, Notonecta glauca, is 
much more painful than the sting of a bee or wasp. 
Bugs are usually regarded as repulsive creatures, our common 
house-bug (the Cimex lectularius of science) being undoubtedly the 
cause of this prejudice, for loathsome and repulsive it certainly is; 
but it must be borne in mind that many bugs are very beautiful in¬ 
deed, and their life history worthy of patient study. 
Our most familiar examples of the Homoptera are perhaps the 
Cercopidas, better known as the spittle insects or “ froghoppers?’ 
The latter appellation has, says Professor Comstock, doubtless grown 
out of the fact that formerly the froth was called “ frog spittle; ” and 
was supposed to have been voided by the tree-frogs from their mouths. 
The name is not, however, inappropriate, for the broad and depressed 
form of our more common species is not unlike the form of a frog, 
while their habit of jumping is very similar. 
These insects pass their whole lives on the plants, on the stems of 
which their eggs are laid in the autumn. The following summer 
they are hatched, and the young immediately perforate the bark with 
their beaks and begin to imbibe the juice. Of this they take such 
quantities that in certain species it oozes out of their bodies continu¬ 
ally from different points in the form of little bubbles, which soon 
completely envelop the insects. 
We are indebted to Buckton for a good illustration of this peculi¬ 
arity of expelling the plant juices at different points of the body, in 
Aphrophora spurn aria. 
From this habit the name of “ cuckoo spits ” is often applied to 
them. The larvae remain concealed inside these masses of spume 
until they have completed their final transformation. 
When the nymph is about to undergo its change into the perfect 
insect it ceases to discharge the juice in the form of spume, and then 
emerges from its concealment. 
If we take the trouble to examine one of these frog-spittles, in the 
centre of the spume will be found a curious looking creature with 
a head peculiarly like that of a frog. This is the larva of a dead, 
and the spume in which it is enveloped is simply the expelled plant 
juices used as a protection. 
“This salivary excretion does not appear to be acrid or injurious 
“to the plants punctured by them for food, otherwise vegetation 
“ would suffer more from the many thousands of cuckoo spits which 
“drain our green produce,”-— Buckton. 
Most of the British species complete their metamorphosis in a 
single season, but little has been done in working up their life history, 
so that there is much need of wide study and patient research. 
To the collector of Hemiptera one thing is pre-eminently notice- 
