INSTINCT 889 



tlie smaller workers, until all the workers were in this 

 condition; we should then have had a species of ant 

 with neuters in nearly the same condition as those of 

 Mjrmica. For the workers of Myrmica have not even 

 rudiments of ocelli, though the male and female ants 

 of this genus have well-developed ocelli. 



I may give one other case: so confidently did I ex- 

 pect occasionally to find gradations of important struc- 

 tures between the different castes of neuters in the same 

 species that I gladly availed myself of Mr. F. Smith's 

 offer of numerous specimens from the same nest of the 

 driver ant (Anomma) of West Africa. The reader will 

 perhaps best appreciate the amount of difference in these 

 workers by my giving not the actual measurements, but 

 a strictly accurate illustration: the difference was the same 

 as if we were to see a set of workmen building a house, 

 of whom many were five feet four inches high, and many 

 sixteen feet high; but we must in addition suppose that 

 the larger workmen had heads four instead of three times 

 as big as those of the smaller men, and jaws nearly five 

 times as big. The jaws, moreover, of the working ants 

 of the several sizes differed wonderfully in shape, and in 

 the form and number of the teeth. But the important 

 fact for us is that, though the workers can be grouped 

 into castes of different sizes, yet they graduate insensibly 

 into each other, as does the widely-different structure of 

 their jaws. 



I speak confidently on this latter point, as Sir J. 

 Lubbock made drawings for me, with the camera lucida, 

 of the jaws which I dissected from the workers of the 

 several sizes. Mr. Bates, in his interesting "Naturalist 

 on the Amazons," has described analogous cases. 



