APPENDIX 539 



Cakile maritima, Eryngium maritimum, Glaucium luteum, &c., the effect 

 of drying is very small. 



NOTE II (page 25) 



The Effect of Sea-water Immersion on the Germinating Capacity 

 OF Seeds and Seed-vessels 



Berkeley, Darwin, Martins, and others, long ago established the 

 capacity of seeds to germinate after prolonged immersion in sea-water. 

 The reader will find a resum'e of their results in the appendix to Mr 

 Hemsley's volume on the Botany of the Challenger Expedition. The 

 subject is well illustrated in the original papers of those authors, and in 

 my later papers on the flora of Keeling Atoll, and on the seed-drift of 

 the Thames. 



I may here remark that the earlier observers often pay more attention 

 to the retention of the germinating capacity after sea-water immersion than 

 to the degree of buoyancy. For this reason I have not been able to 

 make great use of the buoyancy results of Martins, since he frequently 

 does not distinguish between temporary and long-sustained buoyancy, an 

 objection also pointed out by Thuret and Hemsley. 



NOTE 12 (page 27) 



The Buoyancy of the Fruits of Galium aparine 



Norman and Sernander (see p. 172) attribute considerable buoyancy 

 to these fruits on account of the hollow cavity in each. I used to find 

 them in England in floating river-drift in autumn ; and Norman observed 

 them on the Scandinavian beaches. They do not, however, float long, 

 as the cavity is open ; and in two sets of my experiments they sank within 

 a few days. 



NOTE 13 (page 29) 



The Buoyancy of the Seeds of Convolvulus sepium 



This plant seeded freely in 1893 in the Lower Thames Valley, as at 

 Molesey. I kept some of the seeds afloat for thirty-three months, of which 

 the first nine months were spent in sea-water and the rest in fresh-water. 

 One seed, at the end of the period, germinated healthily in the fresh- 

 water. 



NOTE 14 (page 26) 



Other Long Flotation Experiments 



Whilst keeping my collections of Thames sea-drift in water from year 

 to year, I obtained a number of records of long "flotations." Thus in 



