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 larvae and pupae. 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 described for me by Mr. Michael (see 

 Appendix). 



Certain species of Diptera, belonging to the family 

 Phoridae, 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 Linnaeus, 'Aphis 

 formiearum vacca.' A good account of the rela- 

 tions existing between ants and aphides was given 



