448 Studies in the Theory of Descent. 

 SPECIES OF THE GENUS VANESSA, FABR. 



This character of the number of spines will not 

 be considered as too unimportant when we observe 

 how perfectly constant it remains in the nearly 

 allied species. This is the case in the three con- 

 secutive forms, Urines, Polychloros^ and Ichnusa* 

 Now when we see that two species which differ in 

 their imaginal characters present correspondingly 

 small differences in their larvae, this exact sys- 

 tematic congruence indicates a completely parallel 

 phyletic development. 



Exceptions are, however, to be met with here. 

 Thus, Hiibner has united one group of the species 



