352 



C. SKOTTSBKRG 



1. /;/ all casts ciDisidired flcrislic relaliois exist beiwcen the island and one 

 niot/ier coiitinejit. 



2. rite floras of all the islands in question are more temperate in character 

 tha)i that of the mother cojitiiioit on the same latitude. 



This ina\' be true in most cases thanks to the influence of the surrounding 

 ocean; it holds <;o()tl for Juan P'ernandez. 



3. All these islands show many biological peculiarities by which they are 

 distifii^uished. 



Tlie chstin<^uishino characteristics are mainly expressed in endemism. HoOKER 

 referred the etidemics to two cate<^()ries, such as do not show affinity to the plants 

 on the mother continent, and such as, even if belongini^ to endemic genera, are 

 related to continental ones. 



If we turn to the Pacific where, for obvious reasons, only the high volcanic, 

 well watered islands are considered, we find that all of them are distinguished by 

 numerous, in man\' cases also very remarkable endemics. Hawaii stand out above 

 the others and so do Juan Fernandez and Desventuradas; the floras of Tahiti, 

 Samoa, Marcjuesas etc., as well as of Micronesia, are less independent. The degree 

 of s|)atial isolation is not conclusive; the flora of Juan Fernandez is more peculiar 

 than that of Marquesas which are situated much farther away from any continent, 

 and this holds good not only for the angiosperms but also for the ferns. F^n- 

 (lemism in angi()sj)erms is 69% in the former and 50 in the latter; of the ferns 

 about 30 "o in each, but only Juan P^rnandez has an endemic genus. 



4. the i!;e}ieral rule is that the species also fotaid in the mother continent are 

 the most abitndant, the peculiar species are rarer, the peculiar j^enera of contineiital 

 affinity rarer stilf but the plajits with 710 affijiity elseivJiere are often i>ery commoii. 



This is, I supj)ose, true of the islands examined by HOOKKR, with the 

 excej)tion of St. Helena before the arrival of man, but not of Hawaii, nor of 

 Juan l''ernandez. Some of the continental species — Libertia and a few grasses — 

 are abundant, while others are rare, all according to the supply of suitable 

 habitats; atuong the j)cculiar species of continental affinity are many quite 

 common ones, e.g. the endemic species of Acaena, Driniys, Dysopsis, Es- 

 callojiia, (iuniicra, Myrceui^enia (the leading forest tree on Masafuera), Pernettya, 

 Rhafhithannius, ( ]<^n/\ flrijrcroji fruticosus, Uncijiia l)ouglasii\ and of the peculiar 

 genera allied to South yVmerican ones, Xot/iomyrcia is the leading forest tree 

 on Masatierra, where Ochaga/da is also common. To these may be added such 

 common endemics as lioehmeria and the species of /v/^^'-<'7;'rt: and Cop rosm a, unde^v 

 the assumption that related species of lloehnieria, and re{)resentatives of Coprosma 

 and i-agara, once belonged to the neotropical flora. The plants of no affinity in 

 the luother countr\-, that is the nearest continent, are as a rule very local, few 

 are common and many extremely rare. 



Fossil)])- I have misunderstood llooKKK here. When we say that a species 

 is abundant in a country we mean that it is copious; if we call it common, it 

 is widely spread; if we call it rare, it has been rejjorted from a small number 

 of localities only; and if we use "sj)ecies" in plural we mean the same thing. 

 Hut what if HooKHK with "abundant" and "common" wanted to say that these 



