34 ANNALS OF SCOTTISH NATURAL HISTORY 



WATER-BORNE SEEDS. 



By ALEXANDER MACDONALD, M.A. 



THE relations of the wind to the seeds of many plants have 

 been brought out with a beauty of pen and pencil such as 

 the subject deserves, and which has so secured their place in 

 botany that even the children of our Nature Knowledge 

 Classes in Elementary Schools are quite familiar with many 

 of the details and forms of adaptation of wings, balloons, 

 and parachutes to the transportation of seeds. The position 

 of the centre of gravity of many seeds has been obtained, 

 and its curious connection with the hilum, or black spot on 

 the cuticle, pointed out. The tissue at this point is more or 

 less porous, and the little holes readily absorb the moisture 

 of the soil. Frequently the centre of gravity is so adjusted 

 that the seed in falling rests with the hilar spot underneath, 

 and thus in close contact with the wet soil. As soon as 

 the seed comes to rest, the spongy tissue of that part of 

 the organ begins to drink in the moisture necessary for 

 germination. 



There is another method of transporting seeds in which 

 the above arrangement comes even more clearly into play, 

 and that is the transport by water, which we do not think 

 has received all the attention it merits. The distribution of 

 palms and other tropical growths by the waves, and the 

 methods by which many purely water plants are propagated, 

 have been fully elaborated ; while lessons of trust in the 

 uniformity of Nature and hope have been drawn from rice 

 and other grains cast on the waters from patriarchal times ; 

 but there are issues of lesser import quiet little nook- 

 workings of Mother Nature which it is the delight of the 

 amateur naturalist to chronicle. 



The rains of this autumn have called us frequently to 

 the river to note the various phenomena of flooding. One 

 of these was the great masses of floating matter brought into 

 the little creeks and bays of the banks. They consisted 

 mainly of dead leaves, bark, twigs, branches, bits of decaying 

 timber, straw, hay, and other refuse, mixed with which was 

 a vast number of seeds of various kinds. 



