DEVELOPMENT OF THE ANTENN.E OF TERM[TES. 277 



clear from their composition that the XXL organs, in which 

 III is long", are due to the fusing III, IV of the XVII — i. e. 

 (Ill + 15 + 14). 



Development. — The ab ovo expression is that of stage A 

 (PI. XV), joint IIE being in a trilocuiate condition. 



Imago. — These antennae (fig. 9, a) seem to be derived 

 from an uninterrupted development to M (PI. XV), when 

 either (16) abjuncts, as in Nb, or (17 + 16) abjunct, as in MJV. 

 I have not been able to decide which of the two courses is 

 followed. The composition of the flagellum in either case 

 is one of 21 elements, and in this respect is in agreement with 

 those of T. natalensis and bellicosus. 



Worker. — The XVIII-jointed antenna of the major 

 (fig. 9, h) seems to result from a dii*ect development to 

 stage K, the XVII (fig. 9, c) through J to JK, the minor 

 worker antenna (fig. 9, d) being a dwarfed form thereof. 

 All these organs therefore have 19 elements to the flagellum. 



Soldier. — The XVII organ (fig. 9, e) represents a develop- 

 ment from stage A through J to JK and conforms with the 

 worker XVII. The two XVI organs (fig. 9,/, g), in w^hich 

 III is elongate, simple or compound, illustrate a development 

 to J, whilst the form in which III is short (fig. 9, h) is one 

 which stops at H. The rare XV organs (fig. 9, i), on account 

 of the length of III, are taken as developing from stage A 

 through G to G/. AVith the exception of the XVI regarded 

 as an arrest of development at H, the remaining organs 

 appear to have 19 elements to the flagellum, or two more than 

 in the case of the arrested XVI. 



Antennal formula : 



Imago : 



(111111(0000+ 17)iy(16)V(15)VI(14); or 

 -^^■^ ■ "(III 111(0000) IV (17+ 16) V(lo) VI (14) 



Worker : 



XVIII : I II 111(0000) IV (15) V (1-4) VI (13) 



XVII: I II III (0000) IV (15+ 14) V(13) 



Soldier : 



X VII : I II III (0000) IV (15+ 14) V(13) 

 XVI: I II III (0000+ 15+ 14) IV (13) 



XVI : I II III (0000) IV (13) V (12) 



XV: I II III (0000+ 15+ 14) IV (13+ 12)V(11> 



