444 



The wind is another very important and useful agent in seed 

 dissemination. In fact some of the silvicultural systems in Euro- 

 pean and American forestry depend upon this natural agent in the 

 !:e-stocking of the stands of light-seeded trees. For example, the 

 light seed of the Tulip tree in the Alleghany Mountains is known 

 to have been carried by the wind for a distance of a mile. It is 

 fortunate indeed, that two of our most widely planted economic 

 trees, the Ironwood and Silk Oak, possess light, winged seeds 

 which can be carried to some distance by the wind. Saiford states 

 that the seeds of the Ironwood are so light that 'Svhen a handful 

 of them is thrown into the air, they resemble a swarm of flying 

 insects." At Papalinahoa, on Kauai, young Ironwood seedlings 

 continually come up in the sandy soil over 300 feet distant from 

 the parent trees, the seeds being carried there by the wind. This 

 property of the seed, of being carried by the wind, will greatly 

 aid in the distribution of these two species and will make their 

 spread more rapid. 



Birds, also, are in many cases responsible for the distribution 

 of many heavy-seeded plants. In the southern States of New 

 England it is an accepted fact that the spread of the Red Cedar 

 on the abandoned pastures is due to the birds who carry and drop 

 the seeds there. We have only to look upon our own hills to see 

 how the Lantana has been scattered widespread over the land by 

 the turtle-dove. This plant was unfortunately introduced in 1858 

 and has been carried far and wide by birds, which feed on the 

 aromatic berries, not only over the pasture lands, ruining them, 

 but even up to pockets on the cliffs where not even the nimble 

 goats may climb. About the most useful example of seed dis- 

 tribution by birds is found at Lihue, Kauai, and, I doubt not, 

 in many other parts of the islands. Here the fruit of the Java 

 plum is picked by mynah birds for its juicy pulp and the seeds are 

 thus carried over the country and dropped, especially in the 

 vicinity of Huleia Gulch. It is found com.ing up not only through 

 Lantana thickets and on rich soil, but also on the dry- barren 

 ridges where nothing else will grow. The tree is useful for fuel 

 but in growing on these barren places it will serve the much more 

 useful purpose of acting as a ground cover in hindering run-off 

 and preventing the further erosion of the soil. 



Seed distribution by animals possesses the best example in the 

 extensive occurrence of the Algaroba tree in the Hawaiian Is- 

 lands. Introduced as a small slip in 1837 by Father Bachelot it 

 has spread most wonderfully over large areas, so sterile as to sup- 

 port no other tree growth. It now furnishes fuel for the use of 

 man, fodder for cattle and horses, and honey for bees. This wide- 

 spread and rapid distribution of Algaroba is due entirely to horses 

 and cattle. \Viien the pods are eaten, the small, horny seeds are 

 not only not injured by the animals but, on the contrary, are even 

 prepared for cjuick germination by the action of the digestive 



