142 



It quite agrees with this that a stripe appears later than a certain 

 pattern of the spots. In the descriptions of the Pieridae and 

 Phalera amongst others, proofs have been given of the fact that 

 Eimer's hypothesis does not deserve adherence and that J. F. van 

 Bemmelen and Tower are right in defending their opinion that 

 a pattern of spots is more primitive than a stripe. The agree- 

 ment of the pupal pattern with that of the caterpillar instar I 

 was proved to be so great, that an accidental agreement is out 

 of the question. The differences of the pupal pattern with that 

 of the last larval instar are often so great that there is no pos- 

 sibility of the pupal pattern resulting from the remaining parts 

 of the larval hypodermic pigment. 



On these facts I have based the theory developed in Chapter 

 VII, that the pattern of the larval instar / as well as those of 

 the pupa and imago are primitive characteristics. 



The differing armatures of the other larval instars have arisen 

 from specialisation in connection with the mode of life of the 

 caterpillars. 



The later larval instars have arisen from a retardation of the 

 development and with it the setal pattern has had the opportunity 

 of differentiating in various directions. From this we see that I 

 arrive at the same conception of the larval instars as Deegener 

 did on the ground of totally different investigations. 



Summarizing my results, I come to the following conclusions: 



1. The organisation of the thorax is secondary. 



2. The anal segments change in number in the various species 

 of larvae. 



3. Originally all abdominal segments were provided with a pair 

 of legs. 



4. In connection with earlier writers a new nomenclature has 

 been given for the arrangement of the setae : type I, !«, Ih and II. 



5. These various types can be derived from each other. 



6. A metamerically repeated pattern of pigment spots is more 

 primitive than a pattern of stripes. 



7. The change of setae into verrucae is a reversible process. 



