NO. 12 ADAPTATIONS TO SOCIAL LIFE SNYDER 9 



FEAR 



Ants are terrestrial and dominant creatures ; termites, as a rule 

 being blind and soft-bodied, are usually subterranean or secluded 

 in habitat and never dominant. They have been forced to " dig in " 

 to survive and underrun tropical countries. There are a few excep- 

 tions, such as in Hodotermcs of Africa, where the workers are har- 

 vesting in habit and come above ground into the sunlight ; these so- 

 called " workers " and the soldiers have color in the body and have 

 eyes. Ants being terrestrial and aggressive, use their mandibles, 

 sting, and formic acid spray as weapons of offense as well as for 

 defense. Termites have all their weapons located on the head ; 

 mandibles and repugnant frontal gland secretion are used merely for 

 defense. Workers in some genera of termites effectively use their 

 mandibles in the defense of the colony and are more effective than 

 the soldiers. 



Among the most remarkable " adaptations " to social life among 

 termites are the variations in development of the mandibles and 

 frontal glands in the soldier caste. Among the lower termites 

 (Kalotermitidae) , the mandibles of the soldier caste are normally 

 adapted for biting (pi. 3, fig. i), while the frontal gland is rudi- 

 mentary. In many of the higher termites (Terntitidae) , the man- 

 dibles are absent or vestigial and the frontal gland is highly special- 

 ized. Indeed, in the family Rhinotcniiitidae, intermediate between 

 the lower and higher termites, the frontal gland is a specialized organ 

 of defense; in Coptotermes, a sticky, white secretion exudes from 

 a short tube opening. In some genera of the Termitidae the secre- 

 tion is exuded from a nasus or beak (Nasutifermes), (pi. 3, fig. 2) 

 or from the labrum extended into an elongate slender tube forked 

 at the tip ( Rhinotcrmes) , (pi. 3, fig. 4). In species of Armitermes 

 there are both biting mandibles and a nasus (pi. 3, fig. 3). This 

 pungent secretion is more effective against ants — the worst enemies 

 of termites — than are mandibles ; in the specialization of winged 

 termites this gland has passed from a rudimentary, closed (or plate) 

 to an open stage. In other genera (Caprifennes), (pi. 3, fig. 6), Miro- 

 termes, and Orthognathotcrmes (pi. 3, fig. 5)) the mandibles are 

 sometimes markedly asymetrical or at least very elongate and twisted. 

 These mandibles could not possibly be used for biting but they are 

 made use of by bringing together and flipping or snapping particles 

 of earth at the invaders or even flipping away the invaders themselves. 



As Wheeler predicted in 1907, "' wherever the habits of the soldiers 

 have been carefullv studied it has been found that their singular and 



