ENEMIES OF ANTS. 67 
much resembled an ant, that he was himself for some 
time deceived. 
Nor are ants without their enemies. We all know 
how fond birds are of their larve and pups. They have 
also numerous parasites. I have already alluded to the 
mites which are often found in ants’ nests. These are 
of several kinds; one of them, not uncommon in the 
nests of Lasius flavus, turned out to be a new species, 
and has been deseribed for me by Mr. Michael (see 
Appendix). 
Certain species of Diptera, belonging to the family 
Phoride, are also parasitic on ants. As already men- 
tioned, I forwarded specimens to Mr. Verrall, who finds 
that some of them are a new species of the genus Phora, 
and that among them is also the type of a new genus, 
which he proposes to call Platyphora, doing me the 
honour of naming the species after me. I subjoin his 
description in the appendix. 
But the social and friendly relations which exist 
between ants and other animals are of a more complex 
and much more interesting character. 
It has long been known ‘that ants derive a very 
important part of their sustenance from the sweet 
juice excreted by aphides. These insects, in fact, 
as has been over and over again observed, are the 
cows of the ants; in the words of Linneus, ‘ Aphis 
formicarum vacca.’? A good account of the rela- 
tions existing between ants and aphides was given 
