348 EEV. J. T. GULICK ON 



ai e simply more strongly developed varieties. Such being the case, 

 it is folly to ask that the uomeuclature should be based oq some 

 fundamental distinction between species and varieties. 



I'he best nomenclature is the one in which the specific distinc- 

 tions correspond in degree with those that are recognized as 

 specific in other families, and in which a degree of divergence 

 that is considered specific in one part of a genus is considered 

 specific in every part. If the distinctions on which Reeve, 

 Pfeiffer, and Newcomb have founded the species in Makiki and 

 Mauoa are received as specific distinctions, then similar distinc- 

 tions occurring in the forms of other valleys must be recognized 

 as belonging to diff"erent species. I by no means contend that 

 the.se difli"erences should be regarded as specific ; but having re- 

 ceived the three or four forms of Achatinella found in Manoa as 

 good species, it will not do to say that the three forms of Acha- 

 tinella found in Waialei, diff"ering from each other in the same 

 May, are but one species. 



Notwithstanding the diversity of opinion that will always exist 

 as to how many species should be made of the forms occurring in 

 any one valley, every one will agree that the forms of Biolimella 

 and Achatinella found in any one valley are quite distinct species 

 from those found in valleys that are ten or twenty miles distant. 

 The lessons we are drawing from the divergences in this family- 

 are therefore not dependent on any special views concerning the 

 number of species that ought to be received. 



As examples of iutergrading species, examine first the types of 

 Achatinella producta, A.adusta, and A. Buddii from Makiki ; then 

 all the forms of these and the other species of Achatinella found 

 in Makiki ; and tbeiL the forms found in the successive valleys 

 of the whole mountain-range. 



If freedom from iutergrading is received as the necessary and 

 sufficient test of good species, then a multitude of forms that are 

 now only varieties may be turned into good species by burning 

 ,the forests in alternate valleys on either side of this mountain- 

 range. Moreover, if this is the true test of species, the species- 

 maker who throws intergade forms into the fire is quite consistent, 

 even if not quite frank. 



"Whether we call these divergent forms species or varieties, the 

 process by which the divergence has been produced is a matter 

 of equal interest. Indeed, some evolutionists maintain that one 

 of the chief desiderata in the theory of evolution is an explanation 



