66 Annals Entomological Society of America [Vol.1, 



bee, in which the female is clearly a degenerate organism, and on 

 certain specialized instincts, supposed to belong exclusively to 

 worker ants like those of the slave-makers (Polyergus, and For- 

 mica sanguinea). We have therefore to consider, first the in- 

 stincts of the queen, and second, any evidence that may go to 

 show that instinct-changes precede morphological differentiation 

 in the ph^dogeny of the species. 



It is evident that the social insects may be divided into two 

 groups according to the instinct role of the queen. In one group, 

 embracing the social wasps, bumble-bees, ants and teiTnites, the 

 female is the complete prototype of her sex. Even the queen of 

 the slave-making ants manifests in the founding of her colonies 

 all the threptic instincts once supposed to be the exclusive preroga- 

 tive of the worker caste. These may be called the primary 

 instincts. After the colony is established, however, and she no 

 longer needs to manifest these instincts, she becomes a mere egg- 

 laying machine and her instincts undergo a corresponding 

 change and may now be designated as secondary. She thus 

 passes through a gamut of instincts successively called into 

 activity by a series of stimuli which in turn arise in a definite order 

 from her changing social environment. The workers, however, 

 are capable of repeating only a portion of the female gamut, the 

 primary series. In gyn^coid individuals there is also a tendency 

 to take up the secondary series, but in most workers this has 

 been suppressed by countless generations of nutricial castration. 

 The social insects of this type may be called gynaecotelic, to indi- 

 cate that the female has preserved intact the full series of sexual 

 attributes inherited from her solitary ancestors. In these the 

 primary and secondary series w^re simultaneous or overlapped com- 

 pletely, in the gynaecotelic social insects they are extended over 

 a longer period of time and overlap only in part, as social life per- 

 mits the extension of the secondary long after the primary series 

 has ceased to manifest itself. It will be seen that the division of 

 labor which led to the special dift'erentiation of like females into 

 workers and queens is clearly foreshadow^ed in the consecutive 

 diflferentiation of instincts in the individual queen. The second 

 group of social insects is represented by the honey-bees and pro- 

 bably also by the stingless bees (Meliponidse) . In these only the 

 secondary instincts are manifested in the queen, while the worker 

 retains the primary series in full vigor and thus more clearly repre- 

 sents the ancestral female of the species. This type may there- 



