375 



two long' sctiU', and witli wliicli indeed on the last abdoininal 

 segments of the chrysalis this spot beeomes iinited. 



The spot in betwecn might correspond in this case to ehal. 

 dorsolaferalis, which only occnrs on the thoraeic segments of the 

 larva. If this is true, it would appear that this spot belongs to 

 the abdominal segments as well as to the thoraeic and has dis- 

 appeared froni them in a secondary way. If the last abdominal 

 segments of the chrysalis did not show us psendoprimitive con- 

 ditions, this coneeption wonld become more probable. In the same 

 way we might try to find the origin of the spot nnder ni. suh- 

 dorsalis in s. siibdorsalis inferior. 



Instar VII. Imago. J. F. van Bemmelen could tracé the same spots 

 on the body of imagines which had not yet emerged. Here especially 

 m. infrastigmaUs and m. poststigmalis are distinct, the rows on the 

 oral and caudal edges of the segments and the doublé m. swif^/orsa/w. 



Recapitulation. 



1. It has been proved to be possible to reduce the intricate 

 pattern of the last instar of caterpillars to the pattern, as it oc- 

 curs in newly-hatched larvae. 



2. This pattern of instar / agrees in the main with that of 

 the caterpillars of other families. (Type I). 



3. The pattern of the pupa and imago is more like this pri- 

 mitive pattern tlian that of the last instar of caterpillars. 



4. In instar II the linea dorsalis, in instar III the linea 

 stigmalis arises spontaneously i. e., without any stage of transi- 

 tion in the preceding instars. 



Piens napi. Linn. Plate XIV, fig. 8 — 13. 



Egg laid apart on tlie lower and upper sides of cabbage-leaves 

 and Tropaeolum majus L. It resembles that of P. hyassiaie but 

 is 1 '/^ mm. high and has 15 vertical ribs. Duration 6 days. 



Instar I. Length 2'/, mni. Duration 4 or 5 days. 



The colour is transparent, bright-yellow with numerous copper- 

 brown spots in vertical rows. The intestinal canal and the air- 

 tubes shiiu' tlirough. Ilead provided with setae. 



