Colour-groups of the Hawaiian Wasps, etc. 695 



Nov. 13, 1911. 



If I could see the very ordinary-looking Hawaiian species 

 — just like those one may see anywhere in the world — at 

 the least disadvantage as compared with those of the 

 special groups, I should have little doubt of the Miillerian 

 theory — though I should still say that in our islands the 

 groups were formed in the past, by causes no longer opera- 

 tive — but the insignificant forms, like many Nesoprosopis, 

 are extraordinarily successful in life. Yet we have to admit 

 that those coloured to fit special groups have originated 

 from such forms. The general tendency for the latter to 

 belong to open country and the changed condition of the 

 Avifauna are the points that the Miillerian must lay the 

 greatest stress on. I could make the case stronger for him 

 by going into minute detail at considerable length. It 

 would be quite easy to fill a volume with facts concerning 

 these Hymenoptera, dealing with their variations, colours, 

 structures, etc. The true affinities of the species, one to 

 another, becomes very important, when considering the 

 Colour-groups. 



Nov. 10, 1911. 



With the Hawaiian wasps (Odynerus) it must be 

 remembered that, excluding one group of 4 species 

 which are derived from some fairly ancient immigrant 

 from Asia, all the rest are apparently the descendants of 

 a single very ancient immigrant species, though by exces- 

 sive evolutionary change the descendants have now formed 

 distinct genera and structural groups within the islands. 

 There is evidence for the conclusion that the original 

 ancestor was black with yellow bands, such as one now 

 sees all over the world. One must regard all these Colour- 

 groups as having been formed (i. e. started) actually within 

 the islands. 



Conditions under which the Hawaiian Colour- 

 groups MAY HAVE ARISEN. 



Nov. 10, 1911. 



If the Miillerian theory is the right one in this case, I 

 am sure that we must look back to a long past time for the 

 formation of the Colour-groups and the causes are no 

 longer operative. I have in the " Fauna Haw.", under 

 " Aves," given a good deal of detailed information about 



