1902-1903-] Ants in Relation to Flowers. II 



which have none. To the forepart or head pertains most 

 (though not all) of the sensory functions, and it is there, of 

 course, that are placed the powerful and complex mouth parts 

 which play so important a r6U in the work done by Ants. 

 The parts equivalent to our jaw move like the blades of a 

 pair of shears, and open and shut from side to side of the 

 animal instead of up and down as the jaws of vertebrates 

 move. The head bears one pair of eyes situated at the side, 

 and supplementary ocelli, which are situated on the top. 

 The anteunse have one long basal joint, at the end of which 

 the remainder of the antennal joints are articulated at a 

 sharp angle, so that the junction is bent like a knee. 



The mid-part or thorax may be regarded as the seat of 

 locomotion. It is divided into three segments, each of which 

 possesses a pair of jointed legs in all Ants, and two pairs of 

 wings in the Males, and also in the Queen Ants until after the 

 nuptial flight, when they break them off as no longer needed. 

 The wings are naked, membranous, few-veined, and unequal. 

 They are horizontal ; and the lower pair is provided with a 

 series of minute hooks which catch into the reflected pos- 

 terior margin on the upper wings, for the purpose of keeping 

 both pairs together during flight. 



The hind-part of the body or abdomen in all Ants is 

 sharply divided into two. Close behind the " waist," a sharp 

 constriction by which, in all insects, the abdomen is united to 

 the thorax, there is in Ants a second constriction, which is 

 characteristic of the group of Ants in general. The use of 

 this appears to be to permit of increased flexibility at that 

 part of the body. Just as the head is the principal seat of the 

 intellect and the thorax that of locomotion, so the abdomen 

 may be regarded in the light of a chemical laboratory, wherein 

 are carried on not only the processes of reproduction and 

 assimilation, but the manufactory and repository of that 

 important means of offence and defence the formic acid. 

 This powerful irritant is similar in its properties to the poison 

 used by the Wasps and Bees, and also to the irritant fluid 

 found in the Stinging Nettle. Unlike their near relations 

 the Wasps and Bees, Ants are not provided with a sting. 

 Hence when they desire to inflict a painful wound they 

 have first to bite with their powerful shear-like mandibles, and 



