264 tHte BNtOMOLOGIST*S RBCORtl. 



the pupal stage, and that, whilst those of the male continue to develop, 

 those of the female cease their temporary growth, and then perhaps tend 

 to be reduced by absorption, whilst the register of the point of develop- 

 ment reached at the crucial point of growth cannot be removed by absorp- 

 tion, but remains permanently impressed on the pupal skin. Bodine 

 thinks that in the large majority of cases the females have simply not 

 kept pace with the males in the specialisation of their antennae, calling 

 attention to the fact, that in these insects, early oviposition is the rule, 

 and that the struggle of the males to find the females quickly would 

 cause a sudden and extreme specialisation of their antennas without a 

 corresponding influence upon the female. 



Side by side with the increase in the area of the sensitive surface, 

 the differentiation of the hair structures, and a corresponding increase 

 in their efficiency, probably took place. It is not difficult to uncler- 

 stand how the sense-hairs 2 and 3 (PI. II., figs. 4-5), originated from 

 the typical form (fig. 8). Different antennae give different degrees of 

 variation, and whilst the long rigid hair of the second type probably 

 arose before the separation of Jugate and Frenat^, the third type 

 appears not to have been evolved until after the Hesperids and Papi- 

 lionids had branched from the Frenate stem. It is highly developed 

 in the Noctuids and Arctiids. The pits, are very different from the 

 simple sense-hair, yet, in many insects, the pits carry hairs instead of 

 the rods in the more highly developed pits, and, according to Bodine, 

 " different specimens will present various stages of transition from the 

 hair in a comparatively slight pit to a short rod in a deeper one." 

 The cones are a distinct development, and, according to the same 

 author, " must have originated after the separation of the Jugat.e and 

 the Frenat^e, and also after the Hesperiina and Papilionina branched 

 from the latter. All the Frenat/e, except these two super-families, 

 and possibly the Pi/romorphidac/-^ possess these organs. In all of the 

 Microfrenat^e, and in most of the MacrofrenatyE, they are distributed 



one to a segment In some of the Macrofrenat^, however, they 



number more than one to a segment, and in pectinate antennae they 

 have often migrated from the shaft to a position upon the pectinations. 

 .... Among the Satnnnidac, the number of cones to a segment is 



greatly increased It is perhaps worth noting here that, while 



the females are usually behind the males in the development of 

 pectinations, they are not at all deficient in the number or the per- 

 fection of the cones." The surface of thechitinous exoskeleton of the 

 clavola is, as a whole, even in the JugatvE, but " has numerous slender 

 prolongations, which have received the name of ' fixed hairs,' " and 

 which are continuous with, and parts of, the general surface, and are not 

 articulated with the chitin like true hairs. These are not found in 

 the Fkenatve, but the whole surface is "divided up into more or less 

 hexagonal areas (PI. II., figs. 8-9)." Bodine thinks these two kinds of 

 surface indicate a dichotomous division in the line of descent. The 

 surface-marking of the chitin of the clavola, Bodine considers, probably 

 exists in its most primitive condition in the antennje of the 

 Pyralidina (PI. II., fig. 8), in which the general surface, though 

 somewhat smooth, is divided up into more or less hexagonal areas. 

 In the Tortricids, the areas become elongated, in the Tineids, the 

 lengthening is carried much farther, whilst in Ort/i/ia and Cerura, 



*Very close to Zyyaciiidae. 



