36 ^ A NATURALIST IN THE PACIFIC chap. 



the Umbellifera;, the Compositae, and the Labiatse ; whilst in about 

 a third the plants had dehiscent fruits with small seeds, such as 

 are characteristic of the Cruciferae, the Caryophyllaceae, and the 

 Juncaceee. Plants with large seeds, such as those of Nuphar 

 luteum and Convolvulus arvensis, make up only six per cent, of 

 those of the non-buoyant group, the remainder comprising plants 

 with berries, such as Solanum, and others with miscellaneous fruits. 



Of the 80 plants where the seeds or fruits floated more than a 

 week, usually for several weeks, and often for months, 70 per cent, 

 possessed dry, indehiscent fruits, such as those of Hydrocotyle 

 vulgaris, Bidens cernua, Lycopus europaeus, Carex, &c., whilst only 

 6 or 7 per cent, had dehiscent fruits with small seeds, such as we 

 find in Lysimachia and Menyanthes, the remainder being generally 

 characterised by large seeds, such as those of Convolvulus sepium, 

 C. soldanella, Iris pseudacorus, Calla palustris, &c. It would thus 

 appear that, in so far as buoyancy is concerned. Nature has for the 

 most part ignored the small seed and has confined herself mainly 

 to the dry indehiscent fruit. We have already seen that this 

 is also true of the same great sorting-process in the tropical islands 

 of the Pacific, and it doubtless applies all over the world. 



We have now to learn the significance of this distinction 

 amongst British plants between those with and those without 

 buoyant seeds or seedvessels. When we regard the stations of 

 these 80 plants of the buoyant group we find that about 70 per cent. 

 of them are placed by the river, or the pond, or the sea, the fresh- 

 water stations much predominating. But if we include the plants 

 of the moist meadows adjoining the rivers, such as Ranunculus 

 repens, Rhinanthus crista galli, some Cyperaceae, &c., the buoyant 

 fruits or seeds of which are regularly swept into the stream in the 

 time of flood, we shall raise the proportion possessing a water-side 

 station to 80 per cent. On the other hand, about two-thirds of the 

 240 plants of the non-buoyant group, which are enumerated in 

 Note 10, live away from the water-side ; but the proportion of 

 plants with a relatively dry station would be considerably higher 

 than this figure for the whole flora, since my investigations 

 were especially directed towards plants frequenting wet stations, 

 and the number of them is excessive in the list. 



Supposing, however, that our materials were restricted to the 

 260 plants tested by myself, we should obtain highly instructive 

 results, since in a general sense the floating powers of their seeds 

 or fruits were tested to the finish. We place them, let us say, in a 

 bucket of water, and after six months we find that in not more 



