4i8 A NATURALIST IN THE PACIFIC chap. 



whilst the nutlets of Lycopus europaeus are sticky in the dry state 

 and adhere to the fingers on handling. This last-named plant is 

 occasionally to be noticed on rubbish heaps growing with other 

 waste-plants. No such adhesive qualities, whether in the wet or 

 dry condition, came under my notice with Alchemilla arvcnsis or 

 with Lythrum salicaria. With Alchemilla the seed-like fruits fall 

 from the plant, inclosed in the dried-up calyx. The seeds of 

 Cotyledon umbilicus are so minute (I mm. or ^V inch) that they 

 can be compared with Juncus seeds from the standpoint of dis- 

 persal. They are naturally a little sticky and tend to adhere to 

 feathers, but more probably they are transported in adherent soil. 

 The case of Convolvulus sepium is a very remarkable one, and I 

 have referred to it on page 29 and in the notes there indicated. 

 The species of Radiola, Sibthorpia, and Aira have not been tested 

 by me. Dispersion, however, would be favoured by the small size 

 of the seeds in the first two species and by the awned glumes in 

 the case of Aira. 



The distribution of aboriginal weeds might be expected by some 

 to supply data of profound interest to the student of the races of 

 mankind ; and I think the botanist rarely realises how often he 

 tantalises the ethnologist by the remark that certain weeds have been 

 spread by cultivation all round the tropics. De CandoUe many 

 years ago, in his Gcographie Botmiiqtie, gave a list of nearly lOO 

 plants, made up of Old World species naturalised in America and of 

 American species naturalised in the Old World, and quite half of 

 them were classed as plants distributed in one way or another 

 through man's agency. Now this is either a subject of supreme 

 importance or it is of no interest to the student of man's history. 

 If it should prove that birds have done most of this dispersal, then 

 the story of the aboriginal weed would be of little interest in con- 

 nection with the races of man in the New World. 



I will now refer briefly from the standpoint of dispersal to a 

 few interesting Polynesian plants in which man has been in most 

 cases more or less concerned in their distribution. 



Aleurites Moluccana (The Candle-Nut Tree) 



Much interest is attached to this tree, which is found in India, 

 Malaya, and North-east Australia, and occurs all over the Pacific, 

 extending north to Hawaii, south to the Kermadec Islands, and 

 east to Tahiti and Pitcairn Island (Maiden). In the Hawaiian 

 Islands it is often so frequent as to form whole forests, or at all 



