207 



but iiotliiiifi," with tlio other islands, a fairly natural result 

 from their <>'eo<ira]ihieal position. Oahn has nothinii' connmni 

 with Maui, an unnatural state of affairs, and ihi'ce with ITa- 

 waii. The Aloliac have 5 eases of two-island endeniisni and 

 the LcialoJiac -i, ag'ain indieating- the greater ])ower of flight 

 of the latter. 



In the ') eases of three-island endeiuisui the Aloliar have 

 "2 species and the Leidloliae 1 ( Jj. oltiac). all thi'ee heing 

 inacropterons. The only case of more than three-ishmd en- 

 deniism is Aloha ipomoeae, which, from ]noi'])hoU^gieal rea- 

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

 group and a likely ancestor of them all. Lc'ialolia ohuie is 

 also possibly the most primitive of the LclaJolxtc and may he 

 the ancestor of that gronp. 



The stndy of the distribution of these insects gives no 

 support to the theory that the Aloliae are of greater anti(]nity 

 in the Archipelago than the Leialohae : this theory finds its 

 support in the pro])ortional amount of evolution in the two 

 groups. The brachypteronsness of the Alohae may be consti- 

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

 tion. 



It is to be hoped that in the near future enough material 

 will be accumulated from the different islands to enable us 

 to draw juster conclusions and to moTO clearly indicate the 

 evolution of these insects in the Archipelago. 



The reason why isolation should cause variation is not 

 yet understood. That the norm of a few isolated sjXH'imens 

 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)eyon(l tliat 

 limit unexplained. 



The Kan lava flows are very instructive, as they sho\v 

 the manner in which "Hpw/ro.s." or small isolated areas, are 

 cut off l)y the lava flows surrounling them. These lipukas 

 are centers of segregation and must have played an im]iortant 

 part in the evolution of our fauna, especially with Avingless 

 insects. When we consider the enormous age of our islands 

 and the nund^er of such isolated siwts 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. 



