224 A NATURALIST IN THE PACIFIC chap. 



to find a suitable elevation in Fiji. These two or three mountain 

 ferns and lycopods are probably the only vascular cryptogams 

 possessed in common by Hawaii and Tahiti to the exclusion of 

 other groups. (See Note 64.) 



The prevailing Indo-Malayan origin of the ferns and Ijxopods 

 of the archipelagoes of the Fijian area (Fiji, Tonga, Samoa) is 

 so well established in the writings of Seemann, Baker, Hemsley, 

 Christ, and Burkill that there is no necessity to enter into details 

 here. That the stream of vascular cryptogams to Hawaii has 

 proceeded mainly from the Old World side of the Pacific is 

 shown in the circumstance that of the eighty and odd species 

 found outside the group nearly half are from the x^siatic side 

 exclusively and only three from America alone, whilst about a 

 fourth occur in both continents, and a fourth are confined to 

 Polynesia. One point, says Dr. Hillebrand, comes out in strong 

 relief, and that is " the great number of ferns scattered over the 

 long track which leads from the Hawaiian islands through Polynesia 

 and Malaysia to the east coast of tropical Africa." But he 

 adds significantly that " it cannot be inferred from this fact that 

 all the species in question have travelled eastward to find the 

 terminus of their long migration on this group, unless the 

 principle be established, that the formative energy of a species or 

 genus be greatest at the circumference or farthest extremity of 

 its area " (p. 542). 



Though evidently prepared to admit the general eastward 

 trend of plants in the Pacific, Dr. Hillebrand (p. xxviii) puts 

 forward in the case of the ferns the startling view that originally 

 spores of a few simple species have been diffused over various 

 countries and that they have there evolved on parallel lines 

 " predetermined by the structure of the original immigrant " a series 

 of higher forms, so that the same form might have been produced 

 in two widely distant localities, as, for instance, in Ceylon and 

 Hawaii. The editor, Mr. W. F, Hillebrand, gives good reasons for 

 his belief that this does not represent the matured opinion of the 

 author. It is, however, worth noting in this connection that 

 Dr. Karl Mueller has advanced a similar view with respect to the 

 lower orders of plants. (See a translation of his paper in Tracts, 

 and Proc. N. Z. Inst. Vol. 25.) Bearing in mind the known 

 capacity of ferns for dispersal by the winds, an hypothesis of this 

 kind, even if established, seems scarcely needed in the study of 

 fern-dispersal. 



It is probable that many of the ferns and lycopods reached 



