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APPENDIX 



to the unintentional assistance of aboriginal man in his long canoe 

 voyages, and to birds. They came under my notice on almost every 

 coast I visited in warm regions, whether insular or continental. To 

 discuss the various interesting points raised by these plants would 

 be to travel beyond the limits assigned to this work. Not the 

 least important is the presence in some regions side by side with 

 these cosmopolitan plants of peculiar species of the genus. Thus, 

 both the Hawaiian and West Indian Islands have in each case 

 peculiar species of Portulaca. That men and animals have been 

 active factors in the dissemination of some of these plants in inland 

 regions is very evident. Thus, Portulaca oleracea is not only a plant 

 of the sandy beach, but it grows in waste ground away from the sea. 

 There was a story told, I believe, by the late Sir Joseph Hooker, 

 relating to a botanist, who, on landing on one of the uninhabited 

 islands of the Southern Ocean that had never been explored, fell 

 on the sand with his face in the midst of a patch of Portulaca oleracea. 



The above list could be much extended if we added plants not 

 quite so widely spread. Thus, to take the case of Corchorus hirsutus, 

 a typical West Indian shore shrub, also found on the east coast 

 of Africa and in Australia. Its seeds are about 1*5 mm. in size, 

 and the species owes its wide distribution over the warm regions 

 of the globe doubtless to a variety of agencies human and otherwise. 

 Then there are the salt-loving herbaceous plants that are widely 

 distributed in the New World growing on the mud-flats bordering 

 lagoons and coastal swamps, such as Salicornia ambigua and Balis 

 maritima. Although, as is shown in my book on Plant Dispersal 

 in the cases of other species of Salicornia and in that of Batis maritima, 

 these plants are especially well fitted for dispersal by currents, 

 since the seeds germinate in sea-water and the floating seedlings 

 there thrive, it is obvious that considerations other than those 

 concerning means of dispersal are here presented to us. Salicornia 

 is a genus distributed over the greater part of the globe, and Batis, 

 which holds only a single species, is restricted to the New World. 

 Batis maritima has been recently introduced into the Hawaiian 

 Islands, having been first found by Hillebrand in a small island off 

 Honolulu in 1859, and no doubt its introduction was due to human 

 agency. 



Note 22 (p. 343). 



The Azores and their African connections as illustrated by Sphagnum. 



One of the most useful features in Warnstorf's monograph on the 

 Sphagnacece is a list of all the known species of Sphagnum grouped 

 according to the floral regions. It often happens that the student 

 of distribution has to make such a list for himself; but here he finds 

 reference made easy; and the amount of time thus saved is very 

 considerable. But the method has its disadvantages, since much 

 explanatory material is needed to safeguard the student against 

 pitfalls ; and perhaps it would be wisest in the absence of such matter 

 to employ such a list with caution when drawing general inferences. 

 A case in point is represented in this work. At the end of the list 



