28 NATURE STUDIES. 



ants are a nocturnal species, and he had to follow 

 them through the thick scrub, lantern in hand; still, 

 lie satisfactorily settled at last that they obtain the 

 nectar from the galls en an oak, where it must simply 

 .be exuded as an accidental product of injury. The 

 workers take it home with them, and give it to the 

 honey-bearers, who swallow but do not digest it. 

 They keep it in their crops ready for use, exactly as 

 bees keep it in cells of the honey-comb. When the 

 workers are hungry they caress a honey-bearer with 

 their antennas, whereupon she presses back a little of 

 the nectar up her throat, and the workers sip it from 

 her mouth. The honey-bearers, in short, have been 

 converted into living honey-jars. They are thus pas- 

 sively useful to the community, for in this curiously- 

 ordered commonwealth "they also serve who only 

 stand and wait/' 



How could such a strange result as this have been 

 brought about ? Dr. Me Cook, though not himself an 

 avowed evolutionist, has supplied us with facts which 

 seem to suggest the proper answer to this difficult 

 question. He has shown that the rotunds (as he calls 

 them) are not, in all probability, a separate caste, but 

 are merely certain specialised individuals taken at 

 haphazard from the worker-major class. He him- 

 self saw in the nests many worker - majors, which 

 seemed at that moment actually in course of trans- 

 formation into honey-bearers. Now, it is easy enough 

 to understand why these social insects should wish to 

 store up food against emergencies. At all times, the 



