BY H. A. LONGMAN. 21 



"" wonderful partnership " between the noddies and tliis 

 tree, adding, " The birds are sometimes so loaded and clogged 

 with these fruits that they are incapable of flight/' 



The seeds of some of the smaller plants are often con- 

 veyed in mud attached to birds, and in this connection 

 we have Darwin's classic illustration of 82 seeds germinating 

 from a ball of hard earth found on the leg of a partridge. 

 The well-known Plumbago zeylanica, which is firmly estab 

 lished at Mast- Head, has a glandular calyx surrounding 

 the fruit and which falls off with the ripening seeds. This 

 sticky catyx is doubtless responsible for the transfer of 

 seeds, for this widely- spread species is found in most of 

 our scrubs. 



It is with diir.dence that one mentions the possibility 

 of wind disj)ersal in regard to the plants in my list. Of 

 the two Composites found on the island, the Wedelia has 

 no pappus, but the seeds of Gnaphalium luteo-alhum, a 

 very common weed, may well have been blown from the 

 mainland. 



As Mast- Head has been visited at various times by 

 camping parties, it is by no means unlikely that man himself 

 has unintentionally been responsible for the conveyance 

 of some species. 



Only one parasitical plant was found, that being 

 Cassytha filiformis. Species of Lorardhns are very com- 

 monly found on Casuarinas, but they have as yet failed 

 to establish themselves at Mast- Head. 



Xo fungi, lichen or mosses were noted ; perhaps the 

 season and the time of the year were j)artly responsible, but 

 no careful search was made for such small forms as usually 

 escape ordinary notice. 



A large number of Mast- Head plants represent very 

 wideh^-spread species, and among them are some of the 

 most successful colonists of the vegetable world. Tourne- 

 fortia argerdea was collected by Darwin at the Keeling 

 or Cocos Islands, 600 miles from the nearest land. Taking 

 the areas of Continental Asia, Polynesia, Australia, Africa 

 and America, as tabulated hy Hemsley, we find that seven 

 of our plants have the full range : Trihulus cistoides, Suphora 

 tomentosa, Sesuvium portulacastrum, Boerhaavia repanda, 

 Achyranthes aspera, Cassytha filiformis and Casuarina 



