324 , NATURAL SCIENCE . [May 



family Histeridae (ffister, ffetaerius, Myrmetes) and the Stapliyliuids 

 Stenus and Dinarda. The progeny (eggs, larvae, and nymphs) which 

 is sometimes so abundant in the nests, and which ants themselves, 

 in case of scarcity, draw upon as if it were ordinary provision, can 

 also be utilised by the myrmecophiles ; wounded larvae or those 

 bitten by ants are often devoured by the beetles Platyarthrus daviger 

 or Atemeles. 



The cloaca of the nests furnishes a good means for the develop- 

 ment of certain Nematodes and for the nourishment of detriticolous 

 Sarcoptides. 



Generally, it is more often the assemblage of advantages, and 

 not only one of those which are here cited, which has been the 

 motive of introduction and definite installation of a myrmecophile in 

 the home of a species of ant. 



The advantages that a myrmecophile can find in the home of one 

 species are not the same as can be found in the home of another 

 species. For this reason we see Atemeles inhabit successively the 

 nests of two different species : the nest of a Myrmica during the 

 bad season until pairing time, then the nest of Formica to which 

 they confide their progeny, and with which they themselves live to 

 the end of their existence. 



The nutritive liquid stored in the maw and worked up later 

 with the addition of the product of the pharyngeal glands is a 

 precious nourishment, nearly always available in abimdance, and 

 likely to be snapped up, in passing, whilst the ant disgorges for its 

 comrades. This naturally attracts some animals. It is the case 

 with the Lepismidae {Lepismina polypoda) which do not appear to 

 be tolerated amicably by their hosts. More favoured than these 

 Lepismids, the Acarids {AntemwpJiorus uhlmcmni) which support 

 themselves on the same substance, have been accepted by the 

 ants so far as to be permanently carried, and that in spite of 

 their relatively large size. 



It is this same liquid that is immediately and generously given 

 from the ants to the myrmecoxies, as, for example, to Atemeles, 

 which demand it by raising their anterior feet, or to Claviger, which 

 strike with their antennae for it on the head of their host. 



The product of the pharyngeal gland which plays an important 

 part in the working up of the liquid, is the best nourishment for 

 nematode larvae (Pelodera). 



The viscous substance deposited on the surface of the eggs is 

 perhaps used as nourishment by the nymph of Laelaps oophilus, 

 which settles itself upon the packets of eggs in the nest of Formica 

 sanguinea and F. rufibarhis. 



A predisposition of ants to give to the progeny of certain myrme- 

 cophila the same care as to their own, has led to the definite main- 



