207 



but nothing with the other islands, a fairly natural result 

 from their geographical position. Oahu has nothing common 

 with Maui, an unnatural state of affairs, and three with lEa- 

 waii. The AloJiae have 5 cases of two-island endemisni and 

 the Leialohae 4, again indicating the greater jiower of flight 

 of the latter. 



In the 8 cases of three-island endeniism the AJoJiar luive 

 2 species and the Leialohae 1 (L. oliiae), all three being 

 macropterous. The only case of more than three-island en- 

 deniism is Alalia Ipoinoeae, which, from morphological rea- 

 sons, the Avriter has considered as the most primitive of the 

 group and a likely ancestor of them all. LeiaJoha ohiae is 

 also possibly the most primitive of the Leialohae and may be 

 the ancestor of that group. 



The study of the distribution of these insects gives no 

 support to the theory that the Alohae are of greater antiquity 

 in the Archipelago than the Leialohae; this theory finds its 

 support in the proportional amount of evolution in the two 

 groups. The brachypterousness of the Alohae may be consti- 

 tutional and this may have led to a greaier amount of evolu- 

 tion. 



It is to be ho])ed that in the near future enough material 

 will be accumulated from the different islands to enable us 

 to draw juster conclusions and to more clearly indicate the 

 evolution of these insects in the Archipelago. 



The reason Avhy isolation should cause variation is not 

 yet understood. That the norm of a few isolated specimens 

 should differ from the norm of the species only accounts for 

 an alteration of the norm within the limits of variation of 

 the species, but leaves the reason for variation l)eyond that 

 limit unexplained. 



The Kau lava flows are very instructive, as they shoAV 

 the manner in which "hipul-asf or small isolated areas, are 

 cut off by the lava flows surrounling them. These kipul-as 

 are centers of segregation and must have played an important 

 part in the evolution of our fauna, especially with wingless 

 insects. When w^e consider the enormous age of our islands 

 and the niunber of such isolated spots which must have been 

 formed during the building up of them, we can realize to 

 some little extent the enormous help isolation could have been 

 to species formation. 



