BIOLOGICAL PAPERS. 



169 



eyes are small, or about the size of those of the females. The workers 

 are armed with a sting. The workers are very numerous, there being 

 in some of the large nests at least 10,000. 



As with other ants, the workers vary in size, and are termed by 

 many writers as the large-headed and the small-headed individuals, 

 the former being called the worker major and the later the worker 

 minor. However, with the Pogonomyrmex occidentalis it should be 

 distinctly understood that there is no definite distinction between 

 these. One may select eight or ten of the ants and so place them as 

 to have a gradation from the smaller or worker minor to the larger or 

 worker major. But it certainly is not right to select the two extremes 

 and give them an individual name, when the other eight, coming in 

 between, deserve an equal distinction. Tliere are no characters or 

 division of labor to justify such a distinction. 



Although this ant has been endowed by nature with two of the 

 most formidable offensive and defensive weapons known in the insect 

 world — large pointed mandibles for seizing, tearing, and crushing, 

 and a sting that is most painful — and although she is larger than 

 most specimens of ants, yet she is not quarrelsome nor warlike, but 

 on the other hand she is a peaceful and good-natured insect in many 

 respects. This ant permits other species of ants to come on the 



T.^^ ^ 



Fig. 11. Pogonomyrmex occidentalis. Upper two, workers, minor and major; lower two, 

 female and male. ( Draivn by Ella Weeks.) 



clearing and establish their nests or erect their little crescent-shaped 

 piles of loose dirt within a few inches of the base of the mound. I 

 have observed as many as ten of these little nests on one clearing. 

 Neither the nests nor the little ants are molested by the Occident ant. 

 But, on the other hand, the Occident ant is chased and attacked by 



