5-4 JXTS. 



instincts of different queen ants representing not only the common 

 method of colony formation just considered, but also the method- 

 adopted bv the fungus-growers, the temporary and permanent social 

 parasites and tin- slave-makers. In these latter cases the aim still 

 remains the same the bringing to maturity of the first brood and 

 undoubtedly they have developed out of the common type of colony 

 formation. This development, however, could not have takwi plan- 

 by a mere omission or addition of single reflexes, but only through a 

 more or less profound modification of the instinct theme as a whole. 



\Yith the exception of the parasitic females, we find that ants of 

 this sex exhibit all the instincts of their species and it would seem 

 that, like the queen bee, even the parasitic queens must virtually pos>e--. 

 although they never manifest, the worker instincts. This statement, 

 of course, can have no meaning to those who limit instinct to the 

 instinct actions. Yet we must suppose that the parasitic queen ant, like 

 the degenerate queen of the honey-bee, is capable of transmitting to her 

 worker offspring the tendency to forage and construct, although she 

 never manifests this tendency in her own person. We should expect 

 the worker, as an abortive female, to exhibit an abridgment of her 

 mother's instincts, and this, generally speaking, is found to be the 

 case. In the workers, however, under normal conditions, certain of 

 the queen's activities, especially those of nidification, foraging and 

 defence, are exaggerated, while others, such as those of reproduction, 

 are suppressed or kept in abeyance. This intensification of certain 

 tendencies and suppression of others is, of course, eminently purposeful 

 and adaptive. 



In the structural differentiation of the various castes of workers, so 

 elaborately carried out in the species of Atta s. sir., Pheidologcton, 

 Cainponotus. etc., we see a corresponding differentiation of instincts. 

 But, as I have shown in Chapter VII, even monomorphic workers 

 exhibit a tendency to separate into groups of individuals that tempor- 

 arily or permanently perform specific functions in the life of the 

 colony. Both this and the fact that some queen ants that have become 

 parasitic, show as yet in their size and external structure no visible 

 effects of these peculiarities, indicate that instinct leads with changes 

 in the more delicate texture of the nervous system and tissues of the 

 body generally, and that the grosser structures follow more slowly in 

 the wake of these modifications. 



Some authors have laid considerable stress on the deferred instincts, 

 but it is obvious that these, too, are merely instincts that are unable to 

 manifest themselves till the necessary structural apparatus has been 

 developed. Male, female and worker ants all have deferred instincts. 



