The Ants of the Baltic Amber. |9 



amber species of (Ecophylla are somewhat more primitive and more 

 closely related to Gesomyrmex and Dimorphomyrmex than is the recent 

 (E. srnaragdina of the Old "World tropics. The genera Protaneuretus 

 and Paraneuretus are certainly archaic types and related to the single 

 existing species of Anenretus (A. simoni Emery^ of Ceylon, which is 

 justly regarded as a connecting link between the subfamilies Ponerince 

 and DoliclioderincB. Apart from these and possibly a few other 

 exceptions, however, the amber ants are as highly specialized as 

 existing forms and one would not be surprised to find living species 

 of any of the extinct genera turning up in certain little explored 

 portions of the Old World tropics, just as a living species of Geso- 

 myrmex was found in Borneo years after this genus had been disco- 

 vered in the amber. 



Not only is the generic and specific habitus of the amber ants 

 very highly specialized, but their various castes or phases are as sharply 

 differentiated and in precisely the same manner as in our recent forms. 

 Although all this could be readily inferred from Mayr's work of 1868, 

 we find an extraordinary statement by a geologist of high repute, 

 Joseph Leconte, in his well-known ^Elements of Geology" published 

 in 1884. Misled by the fact that nearly all the Miocene ants preserved 

 in the lacustrine formations of Florissant, Oeningen and Radoboj are 

 males and females, he says: ,,It is probable that ants at first were 

 only winged males and females living in the open air like other in- 

 sects. The wingless condition and the neutral condition are both 

 connected with their peculiar social habits and instincts, and have 

 been gradually developed along with the development of their habits 

 and instincts. It is probable that all these remarkable peculiarities, viz. 

 the wingless condition, the neutral condition, the wonderful instincts, 

 and organized social habits, have been developed together since the 

 Miocene Epoch." So far is the latter portion of this statement 

 from being true that we may confidently assert that the differentiation 

 of the worker caste among these insects must have been completed 

 before the beginning of the Tertiary and therefore not later than the 

 Cretaceous or even the Jurassic or Triassic periods. 



In two of my former publications^) I stated that I was unable 

 to detect any evidence that the ants of the Baltic amber had developed 

 any dimorphism or polymorphism within the limits of the worker caste 



1) Comparative Ethology of the European and North American Ants. Journ. 

 P.sychol. u. Neurol. XIII. 190d, pp. 404—435. 4 pl.s. and 6 text-figs; and Ants, their 

 Structure, Development and Behavior, Columbia University Press, 1910, p. 174. 



2* 



