ALASKA FORESTS 245 



and a count of the rings showed none older than ninety or 

 a hundred years, while on Kadiak and Wood Islands the 

 oldest growth was found to be between 125 and 150 years, 

 with some few rotten stumps possibly older. This differ- 

 ence in age of entire groves so near together allows the 

 inference that the older has furnished the seed for the 

 younger, and that the spruce has wandered from Kadiak 

 to Long Island. 



This suggests another influential factor in the distribu- 

 tion of trees, namely the winds as carriers of seed: not 

 only the direction of the wind but the character of the 

 weather accompanying it influence this distribution. In 

 wet weather the cones close; it is only in dry weather that 

 they open and release the seed. To secure the southwest 

 extension of trees along the Alaska Peninsula, it would be 

 necessary that, after the ripening of the seeds and during 

 their release from the cones, which takes place gradually 

 through the winter, the winds should be dry and blow 

 from the north and east. But the contrary usually hap- 

 pens, for from September to May there is a constant suc- 

 cession of southeast and south winds, and the air is heavily 

 charged with moisture. For this reason the spread of the 

 species is at least retarded, and only when, as may occa- 

 sionally happen, favorable wind direction at the right time 

 coincides with a seed year, is progress possible. That 

 seed production as far west as Kadiak can be most prolific 

 was evidenced by an enormous crop of cones which 

 ripened in 1898, turned brown, and remaining on the 

 branches in the summer of 1899, gave the trees at a dis- 

 tance the appearance of having been killed by fire. How 

 much of this seed is good and capable of germination, and 

 how often seed years occur could not be ascertained. 



That trees can at least exist farther west, on the Aleu- 

 tian Islands, is proved by a few scattered spruces at 

 Unalaska, planted by a Russian priest in the year 1805. 



