LONGIROSTRES AND RHYNCHOLOPILE. 



DIAGRAM 6. 



Distribution of the LONG-IROSTKES 



• * * 



Total 

 Percentage 



M» 



• t • 



»•• 



... 64 sp 



... 20% 



DIAGRAM 7. 



I 



Distribution of the Rhyscholophji. 



Total 

 Percentage 



■ 



••• 



M sp 



35°/ 







5 



3 



As the highest division LONGIROSTRES and the section Riiynciioloph.e practically 

 include all the " beaked forms" from which the upper percentages in diagram 3 (p. 45) are 

 derived, it seems better to discuss them side by side. It has, however, to be recollected 

 that these sections— the Rhfncholopm especially— include also forms that possess corollas 

 exhibiting the other characters that indicate a higher specialisation of structure but 

 without having happened to develope long beaks. The two long-beaked sections require 

 no detailed consideration. They are almost equal in numbers and in degree of speciali- 

 sation of structure; they exist side by side and are uniformly distributed; they have 



soriginated in the same provinces and apparently contemporaneously; and finally, while 



quite distinct from each other, they exhibit 



same degree of relationship to th 



B HYNCHOLOPHiE. Both of them appear from diagram 6 to have been evolved towards th 



quatorial extremity of the Ch 



meridian of distribution. We have already been led 



to conclude from morphology that they form the most highly specialised d 

 conclusion has shown the probability of its being tb 



th 



division most 



tly evolved; it 



present distribution shows that this i 

 It has not extended, along its own 

 during the most recent northern migration 



not probable merely, but almost certainly the case, 

 meridian even, as far as the Circumpolar province 



That it has not done so in previous ones 



seems certain not only from its complete absence from the Circumpolar prov 



y 



but 





