OBSERVATIONS ON BUTTERFLIFS ¢ HORNETS. 341 
sap exuded by this, probably, diseased tree is peculiarly attrac- 
tive there can be no doubt. There were, for instance, at one 
time, this afternoon, six of the Large Tortoiseshell butterflies 
settled on its trunk, at the same time, either feeding or looking 
for a place—a beautiful sight to see, for the wings of several, if 
not all, would often be spread to the sun at the same time. 
Various flies, too, are always about it, and I once saw a Rose 
Beetle apparently feeding, for a hornet of the large kind, coming 
to the same place several times in succession, walked over him, 
each time, without appearing to notice he was there—the beetle 
keeping perfectly still. When the evening falls a number of 
moths—small for the most part-—take the place of the butter- 
flies. 
I have only seen one other tree—also a small lopped oak— 
from which there was a similar but much less extensive exuda- 
tion, and here, too, there were two or three Red Admirals 
gathered. 
Some days after this I noticed that the flow of sap from this 
tree was much diminished. In consequence, the smaller hornets 
were not coming so frequently, but, a little later, the flow had 
again increased, and was much the same as before. They were 
then correspondingly busy, but I did not again see any individual 
of the larger kind. The failure of the sap is felt by the hornets 
much sooner than by the butterflies, no doubt because the 
slender proboscis of the latter is enabled to deal with it in 
quantities, and in situations insufficient or impracticable for the 
latter. 
