ANTS AS DOMINANT INSECTS. 3 



and bees in their struggle for existence. The ants neither restrict their 

 diet, like the termites, to comparatively innutritions substances such as 

 cellulose, nor like the bees to a very few substances like the honey and 

 pollen of the evanescent flowers, nor do they build elaborate combs of 

 expensive materials, such as wax. Even paper as a building material 

 has been very generally outgrown and abandoned by the ants. Waxen 

 and paper cells are not easily altered or repaired, and insects that are 

 wedded to this kind of architecture, not only have to expend much time 

 and energy in collecting and working up their building materials, but 

 they are unable to move themselves or their brood to other localities 

 when the nest is disturbed, when the moisture or temperature become 

 unfavorable or the food supply fails. The custom of depending on a 

 single fertilized queen as the only reproductive center or organ of the 

 colony has also been outgrown by many ants. At least the more domi- 

 nant and successful species have learned to cherish a number of these 

 fertile individuals in the colony. Finally, the manifold and plastic 

 relationships of ants to plants and other animals are in marked contrast 

 with the circumscribed and highly specialized ethological relationships 

 of the social bees and wasps. The termites undoubtedly resemble the 

 ants most closely in plasticity, but the careful studies of Grassi and 

 Sandias, Sjostedt, Froggatt, Silvestri, Heath and others, have shown 

 that these insects, too, are highly specialized, or one-sided in their devel- 

 opment. This is best seen in their extreme sensitiveness to light, for 

 this practically confines them to a subterranean existence and excludes 

 them from many of the influences afforded by a more varied and illu- 

 minated environment. 



There can be little doubt that the ants have become dominant through 

 their exquisitely terrestrial habits, a fact which Espinas (1877) was, I 

 believe, one of the first to notice. He says: "Ants owe their supe- 

 riority to their terrestrial life. This assertion may seem paradoxical, 

 but consider the exceptional advantages afforded by a terrestrial 

 medium to the development of their intellectual faculties, compared 

 with an aerial medium! In the air there are the long flights without 

 obstacles, the vertiginous journeys far from real bodies, the instability, 

 the wandering about, the endless forget fulness of things and oneself. 

 On the earth, on the contrary, there is not a movement that is not a 

 contact and does not yield precise information, not a journey that fails 

 to leave some reminiscence ; and as these journeys are determinate, it is 

 inevitable that a portion of the ground incessantly traversed should be 

 registered, together with its resources and its dangers, in the animal's 

 imagination. Thus there results a closer and much more direct com- 

 munication with the external world. To employ matter, moreover, is 



