115 



two Umg setae, and with which indwHl on tho last abdominal 

 segments of the chrysalis this spot becomes united. 



The spot in between might corri^spond in this case to chal. 

 donolateraliif, which only tKVurs on tlie thoracic segments of tho 

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

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

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

 segments of the chrysalis did not show us p8eud«>primitive con- 

 ditions, this conception would become more probable. In the same 

 way we might try to find the origin of the spot under m. .tuh- 

 tloi'nalis in «. gubdorsalis inferior. 



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

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

 III. infnistigmalig and in. posMitjinalis are distinct, the rows on the 

 oral and caudal edges of the segments and the double in. suhdorsalis. 



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 than that of the last instar of caterpillars. 



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

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

 tion in the preceding instars. 



Pieris napi. Linn. Plate V, fig. 8 — 13. 



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

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

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



Instar 7. Length 2'/; mm. 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 shine through. Head provided with setae. 



