XXVII SAPOTACE^ ' 373 



transport these large stones or pyrenes to that group. The extent 

 of ocean to be crossed is no doubt much greater, but this area of 

 the Pacific is not without some small half-way groups that would 

 serve as resting-places. 



That fruits of the order Sapotaceas are much appreciated 

 by fruit-pigeons is already known. We learn from Kirk that 

 the fruits of Sideroxylon costatum (Sapota costata) are a favourite 

 food of the New Zealand fruit-pigeon, the fruits, about an inch 

 long, containing three hard crescentic bony seeds nearly as long as 

 the fruit. The natives of Vanua Levu informed me that a Fijian 

 species of Sideroxylon with hard seeds about an inch long was 

 much appreciated on account of its fruit by the pigeons. I found 

 the hard, sound seeds of a species of Sapota, two-thirds of an inch 

 (or 16 mm.) in size, in the crop of a Fijian fruit-pigeon. The 

 similarly large seeds of a species of Achras were identified by Mr. 

 Charles Moore, of Sydney, amongst a collection of seeds, &c., 

 found by me in the crops of fruit-pigeons shot in the Solomon 

 Islands (Guppy's Solomon Islands, p. 293). It may be added that 

 the difficulty concerned with Sideroxylon in Hawaii is the difficulty 

 concerned with other large-seeded Sapotaceous trees in Fiji and 

 New Zealand, and the same explanation must be applied to all. 

 Some further remarks on the Sapotacea; in the Pacific are given 

 below. 



The mode of dispersal of some of these genera is illustrated 

 in other regions. The berries of Pleiosmilax, a subgenus of 

 Smilax, are well suited for aiding the dispersal of the genus by 

 frugivorous birds ; and we learn from Prof Barrows (Weed, p. 42) 

 that in the United States crows feed on the fruits of Smilax 

 rotundifolia and disperse the seeds. On the other hand, it is not at 

 first sight easy to understand how a genus like Gouania has been 

 distributed over the tropics of the globe, since it possesses dry 

 capsular fruits about half an inch across, separating into three 

 woody cocci that appear most unlikely to attract birds. The same 

 difficulty exists, however, with other dry-fruited widely-ranging 

 genera like Alphitonia and with many of the Euphorbiaceae. 



Amongst these genera found in Hawaii and Fiji to the 

 exclusion of Tahiti we can at times detect indications of the 

 operations of a polymorphous species as described in Chapter 

 XXVI., when a widely-ranging highly variable species is associated 

 in some groups with peculiar species. We see some evidence of this 

 in the genera Gouania, Maba, and Eurya, alluded to on a previous 

 page. (See also Bot. CJiall. Exped., iii. 1 34, under " Gouania.") 



