270 CLAUDE FULLER. 



Should the developing* organ reach stage N it would by a 

 XX-jointed expression. This I believe it occasionally does^ 

 but such of those examined as would have been XX-jointed 

 had been reduced to XIX by capricious fusings such as 

 (11 + 10) which took place as in stag'e BE ov of (13 + 12) as in 

 stage Grll. The total elements in the flagellum of all patterns 

 may be regarded as 21. 



Major Worker. — These antennae develop from stage C to 

 J; at this point (15 + 14) are abjuncted as one joint (stage 

 J/v). The organ then passes through JL, JM and JN to JO. 

 It, therefore, has a slightly greater development than the imago 

 organ ; but this is confined to III and leads to the peculiar 

 buffer-shape of that joint. The number of elements of the 

 flagellum is 21. 



Minor Worker. — The development of these organs either 

 follows the direct route C to K and they become XVIII- 

 jointed, or diverges from J to JK, by the fusing of (15+ 14). 

 In both cases the flagellum elements are not less than 19 and 

 may be 21. 



Major kSoldier. — A few of the major soldier antennte 

 develop along the same route as do those of the minor and 

 become XVII-jointed. Some following the C, J, Jii route pass 

 from JM to jNh and become XYIII by the abjunction of (16). 

 Others follow the direct route C to M, when they remain 

 XVIII-jointed due to the suppression of articulations 

 developing in III, so that III comprises (0000 + 17 + 16), 

 or they pass to the stage Nb and become XlX-jointed, III 

 representing (0000 + 17). The flagellum in all soldier 

 antennas is therefore composed of 21 elements. 



Minor Soldier. — The antennre develop from C to J and 

 from J through jK to Jil/, at which stage one joint, more or 

 less compressed in appearance, forms a (0000 + 17 + 16) com- 

 bination. Here, as in the imago and worker major antennas, 

 the total of flagellum elements is 21. 



Reduced to a formula the various antennas are composed as 

 follows : 



