4 i 6 A NATURALIST IN THE PACIFIC chap. 



their collections (see Note 82). Of these 22 occur in continental 

 regions on both sides of the Pacific, 13 are natives of the Old World 

 alone, and two only are seemingly American exclusively, namely, 

 Waltheria americana and Teucrium inflatum. The first is claimed 

 to be American because most species of the genus are American, 

 but it is now widely distributed in the Old World as well as in 

 America. The second, though widely distributed in tropical 

 America, has strangely enough only been found in the islands of 

 the Western Pacific. 



The important point is thus brought out that although in Captain 

 Cook's time the food-plants cultivated by the Polynesians, such as 

 the banana, the breadfruit, the taro, and the yams, were almost 

 exclusively Asiatic in origin and bore Malayan names, a large 

 proportion of the weeds were not exclusively Asiatic, but occurred 

 in America as well as in the Old World. The inference to be drawn, 

 however, is not, as Dr. Seemann implies, that the Polynesians de- 

 rived several of their weeds from America (since with few excep- 

 tions all the aboriginal weeds named in Note 82 occur in the Old 

 World, and in more than a third of the plants in the Old World 

 only), but that many so-called cosmopolitan weeds were distributed 

 very much as they are now, when the Polynesians brought their food 

 plants from Indo-Malaya into the Pacific. 



Weeds follow the cultivator in all climates ; and it is very natural 

 that, as Mr. Hemsley points out, plants which seem to owe their 

 wide dispersal to cultivation are not found in Australia (Bot. Chall. 

 Exped., iii, 142). The Australian native as a rule cultivates nothing. 

 Yet I fancy that man's share in weed dispersal is as often as not 

 merely restricted to producing the conditions favourable to the 

 growth of weeds, and that the seeds are often brought by birds and 

 other agencies. Many weeds of the genera Atriplex, Polygonum, 

 and Ranunculus are dispersed by partridges in England, and I have 

 often found the uninjured fruits of the plants in the stomachs of 

 these birds. Many weeds, like Prunella vulgaris, Plantago major, 

 Capsella bursa-pastoris, Luzula campestris, and several others named 

 in Note 43, possess seeds or fruits that become " sticky " when wet, 

 and would readily adhere to a bird's plumage. 



We can also say of tropical weeds that many of them are dis- 

 tributed by birds. In the crop of a dove in Hawaii I found a 

 number of the small dry fruits of Waltheria americana, the widely 

 spread tropical weed before mentioned, and of another weed of the 

 order Compositae. On the bare rocky peak of one of the Vanua 

 Levu mountains the only plants found growing were Oxalis corni- 



