540 A NATURALIST IN THE PACIFIC 



several cases, as with Bidens cernua and different species of Carex, 

 germination of the floating fruit took place in the water after a period of 

 two years. The same is also true of the seeds of Iris pseudacorus and of 

 the drupes of Sparganium ramosum. The last-named remained afloat in 

 the vessels, with the seed still sound, after four years ; and the fruits of 

 Carex paludosa germinated afloat after three years in water. Many drift 

 fruits and seeds did not germinate freely in the vessels until the second 

 spring, that is, after a lapse of eighteen months ; and in those cases where 

 the experiments were still further prolonged, a few germinated in the 

 vessels in the third and sometimes even in the fourth year. 



NOTE 15 (pages 33, 280) 



The Occurrence Inland of Silene maritima 



Prof. Schimper appeared to be in doubt as to the inclusion ol this 

 littoral plant amongst those found in elevated mountain districts. 

 However, an interesting note on the occurrence of this plant on the 

 summit of one of the inland Norwegian mountains is given by Sernander 

 (p. 405), and is referred to by me on page 280 of this work. 



NOTE 16 (page 34) 



The Buoyancy of the Seeds or Fruits of the British Beach- 

 plants THAT ALSO OCCUR INLAND 



My experiments in the case of Armeria vulgaris, Artemisia, Cochlearia 

 officinalis, Plantago, the maritime forms of Spergularia rubra with and 

 without winged seeds, and Silene maritima disclose little or no floating 

 capacity even after prolonged drying. Thuret obtained similar results for 

 the Spergularia. It is unlikely that other plants of the group possess any 

 floating power worth speaking of. As indicated in Note 71, the fruits of 

 Raphanus maritimus float only for 7 to 10 days. 



Nature disperses the fruits of Armeria vulgaris inclosed in the 

 persistent calyx ; but in this condition they float only for 2 to 4 days in 

 sea-water, and the buoyancy of the capsule and seed is still more limited. 

 They are sufficiently light to be blown some distance by strong winds, and 

 the stiff hairs would cause them to adhere to a bird's plumage in the case 

 of gulls nesting where the plants grow. 



Reference to Matricaria inodora is made under Note 18. 



NOTE 17 (page 35) 



The Buoyancy of the Seeds or Fruits of the Group of British 

 Littoral Plants that frequent Salt Marshes and Muddy Shores 



Aster tripolium. The achenes, with or without the pappus, sink in 

 fresh and salt water in a day or two even after a year's drying. 



