. Ants; their structure, development and behavior. deed, varyquite independently of other portions of the brain and in the manner S ANTS. noticed by Furel. In a .similar series of Formica (jlaciaUs (Fig. 29),however, there are no such striking differences in the three pedunculate bodies (pb ) are as highly developed in the female asthey are in the worker, and they can hardly be said to be vestigial inthe male. In Ihcniolc instabilis ( Fig. 30), too, the female and soldierhave well-developed pedunculate bodies, though these seem to be insig-nificant in the male. \Yhile, therefore, th
. Ants; their structure, development and behavior. deed, varyquite independently of other portions of the brain and in the manner S ANTS. noticed by Furel. In a .similar series of Formica (jlaciaUs (Fig. 29),however, there are no such striking differences in the three pedunculate bodies (pb ) are as highly developed in the female asthey are in the worker, and they can hardly be said to be vestigial inthe male. In Ihcniolc instabilis ( Fig. 30), too, the female and soldierhave well-developed pedunculate bodies, though these seem to be insig-nificant in the male. \Yhile, therefore, the male brain in all thesespecies, apart from the huge development of its optic ganglia and stem-matal nerves, is manifestly deficient, I doubt whether we are justifiedin regarding the brain of the female as being inferior to that of theworker. It is true that the worker brain is relatively larger, notwith-standing the smaller eyes and stemmata, or the complete absence of thelatter, but I would interpret this greater volume as an embryonic char- D. FIG. 30. Heads of soldier (A), worker (B), female (C), and male (D} ofPheidole instabilis, drawn under the same magnification, with brain, eyes and ocelliviewed as transparent objects. (Original.) Letters as in Figs. 28 and 29. acter. The worker is, in a sense, an arrested, neotenic or more imma-ture form of the female, and it is well known that the volume of thebrain and of the central nervous system in general is much greater inproportion to that of the body in embryonic and juvenile than in adultanimals. Forel was probably influenced in his interpretation by theview, so long accepted, but now abandoned by myrmecologists, that the THE INTERXAL STRUCTURE OF ANTS. 57 queen ant is a degenerate creature like the queen bee. In future chap-ters of this work I shall have occasion to show the untenability of thissupposition in the light of recent The foregoing considerations do not, of course, invalidate Dujarclinshypothesis.
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Keywords: ., bo, bookcentury1900, bookdecade1910, booksubjectants, bookyear1910
