IV INSECTS INHABITING ANTS'-NESTS 1 83 



will disclose a greater number of the parasites of this latter 

 class. 



Much attention has been given to the relations l)etween ants 

 and their guests by Wasmann.^ He arranges them in four 

 categories : 1, " Symphily " for the true guests, which are fed and 

 tended by the ants, the guests often affording some substance 

 the ants delight in ; 2, " Metochy," the class of tolerated guests, 

 being so far as is known not disagreeable to the hosts ; 3, 

 " Synecthry," including those Insects, etc., to which the ants 

 are hostile, but which nevertheless maintain themselves in the 

 midst of their foes ; 4, Parasites, dwelling in the bodies of the 

 adult, tir of the young ants. Many of these ants'-nest Insects 

 present a more or less perfect resendilance to the ants in one or 

 more points, such as sculpture, colour, size, or form. To these 

 resemblances Wasmann a,ttaches great importance. "VVe should, 

 too, notice that some of the inquilines " have become acquainted 

 with the movements and habits of the ants, and stroke them (as 

 the ants do one another) to induce them to disgorge food in the 

 manner we have alluded to. According to Janet, ants of the 

 genus Lasius are infested by Acari of the genus Antennojjhorus. 

 The ants carry the mites, which assume positions so as not to 

 cause greater inconvenience than is inevitable. Moreover, the 

 ants give food to the mites when requested, and behave in a most 

 obliging way to them, though there is not any reason for supposing 

 that in this case the ants derive any benefit from the Symphily. 



The relations between ants and plants have been of late years 

 much discussed. We have already briefly alluded to the subject 

 wlien speaking of the I'seudomyrmini. We will here only remark 

 that ants frequent plants not only for the purpose of securing the 

 sweet stuff excreted by the Aphidae that live on them, but also 

 for the sake of getting the sweet products the plants themselves 

 afford. Mr. Aitken, speaking of ants in India, says : " I have 

 come to the conclusion that one of the most important sources of 

 foo(_l-supply which ants have is the sacchariferous glands to be 

 found at the bases of so many leaves." It is supposed that the 

 ants are on the whole beneficial to the plants that thus afford them 

 supply ; and this fact is considered by many to afford an adequate 

 explanation of the existence of these interesting relations. 



1 For a summary of tliis subject see Wasmann, Congr. internal. Zool. iii. 1896, 

 pp. :ill-440. " For explanation of this term see vol. v. p. 524. 



