ANTS AND PLATYARTHRUS HOFFMANSEGGII. 129 



peasant towards entomologists: — Peasant iroinan: "Bonjour, madame, 

 avez-vous beaucoup ramasse?" Kntoinoloiiht: " Un pen, madame." 

 Peasant: " Qu'est-ce que vous faites avec ces papillons — la'?" Ento- 

 7)iolo(iist: "Pour faire collectione." Peasant: "Ehbien! Pourquoi ? 

 Pour manger ? " (tres serieusement) ! ! 



Ants and Platyarthrus hoffmanseggii. 



By C. CEAWLEY, B.A., F.E.S. 



It is generally stated by entomologists that ants take no notice 

 whatever of the small white crustaceans that live in their nests. The 

 following notes will show that under certain circumstances the ants 

 interfere with their guests, and generally seem aware of the presence 

 of strange ones. 



It must first be noted that the Platijarthri themselves often shun 

 contact with their hosts. If a Platyarthrus be observed carefully in 

 an artificial nest, it will be noticed that it turns aside whenever it 

 touches an ant; and when, as often happens, an ant steps on the back 

 of a Plati/arthnis, the latter remains motionless for a few seconds 

 before hurriedly moving away. The ants also often turn round with 

 open mandibles when a Platijarthrus passes close to them. 



In August, 1896, an ant {Lasius niger) was observed, while walking 

 about the nest, to rest her forefeet on a Platyarthrus. The latter 

 raised its tail, and the ant started back and went away. A similar 

 thing was noticed not long after, in the same nest. Also in September, 

 1896, a L. niyer was seen lifting a Platyarthrus that had been intro- 

 duced from a nest of L. jlarus, and a few minutes later another of 

 these strangers, on being examined by an ant, raised its tail, and the 

 ant immediately went away. Another stranger, on entering the nest, 

 was met with every appearance of hostility. 



Again, on August 12th, 1897, I put two fullgrown Platyarthri 

 from a nest of L. flarus into one of L. niger. Soon after an ant 

 picked up one of them by the edge of its shell, and carried it to the 

 door of the nest, then dropping it. The Platyarthrus ran back into 

 the nest, and no more notice was taken of it. 



On July 11th, 1898, I brought some Platyarthri from a nest of L. 

 flarus in Surrey, and put them into a nest of L. niger taken in Oxford- 

 shire. The ants attacked them, killing one and subsequently eating 

 it, and driving all the rest from the nest. (This nest of L. niger, as well 

 as the others mentioned above, possessed Platyarthri of its own). A 

 few weeks later I put some from a strange nest of L. niger in the 

 neighbourhood into ray nest of L. niger. The ants attacked them at first, 

 but eventually desisted, and the J'latyarthri were allowed to remain 

 unmolested, with the exception of one, slightly injured in capture, 

 which was devoured. Three days afterwards this nest remained too 

 long in the sun, whose heat through the glass cover killed all the 

 Platyarthri. The ants dismembered the dead bodies and used them as 

 food. To replace these Platyarthri, 1 transferred several the following 

 day from another nest of the same species of ant. These Platyarthri 

 were examined by the ants, but not molested. 



Again, on September 22nd, 1899, I put three Platyarthri from a 

 nest of Myrtiiica scahrijindis, into a nest of L. niger. On visiting the 



