FLORAL AFFINITIES 417 



southern flora passed over them, for of course southern 

 plants penetrated northward just as animals did. Mr. Sereno 

 Watson,* for example, in referring to the flora of the small 

 island of Guadalupe off the west coast of California, remarks 

 that the presence of so many South American types suggests 

 that this, and the similar element which characterises the 

 flora of California, may be due to some other connection be- 

 tween these distant regions than the one now existing. He 

 expresses the opinion, too, that all the peculiarities in the 

 western floras of both continents had a common origin in an 

 ancient flora which, prevailed over a wide, now submerged 

 area, and of whose character the former are the partial 

 exponents. 



As regards 'the question whether the northern plants 

 growing in Chile and Argentina can really be regarded as 

 indigenous or introduced, Professor Hackel has recently dealt 

 with this problem from a new point of view. He shows that 

 the species which are either identical with European or North 

 American plants, or such as may be considered as varieties or 

 sub-species of them, increase rather than diminish as we go 

 further south. Thus he records fifty-one plants from 

 southern Patagonia and Tierra del Fuego belonging to this 

 group, which he regards as undoubtedly indigenous to these 

 countries. Thirty others may possibly have been introduced 

 by man. Professor Hackel thinks that their southward 

 advance could only have taken place step by step on a land 

 surface. If these plants had passed across Central America 

 and along the Andes, we should find relict colonies of the 

 species, or at least their modified descendants, scattered on 

 their route of migration. Only very few of such occur in 

 Bolivia, Peru and Ecuador, and these have the appearance 

 of having reached these localities from the south rather than 

 from the north. When we examine the composition of this 

 remarkable flora in the Magellan district, we notice, according 

 to Professor Hackel,f that the majority of the species belong 

 to the grasses (Gramineae) and the sedges (Cyperaceae). The 

 dicotyledons only comprise fifteen species. This he believes 



* Watson, Sereno, " Flora of Guadalupe Island," p. 112. 

 t Hackel, E., " Flora der Magellanslander," pp. cxi cxv. 

 L.A. E B 



