22 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Notwithstanding the much greater proximity of the Japan 

 islands to the equator, there is much similarity in the climatic 

 conditions of the two groups, especially between those of England 

 and Nippon, or Honda, the climate of the North of Scotland ap- 

 proaching more nearly that of Southern Yesso. Thus the 

 isothermal line for 50° Fahrenheit which passes through Ireland 

 and England between the 50th and 55th parallels curves below 

 the 45th where it passes through Japan, which is the same as 

 saying that the average yearly temperature of the two countries 

 where that line passes, and to a certain distance on each side of 

 it, is the same ; but there the similarity ends. Turning to the 

 other important factor in climatology, rainfall and atmospheric 

 humidity, we find a great disparity between the two. The annual 

 rainfall in the south-eastern counties of England rarely exceeds 

 25 inches, in the southern and western counties there is sometimes 

 registered from 80 to 35 inches, in parts of Devonshire and 

 Cornwall as much as 50 to 60 inches, and in particular localities, 

 but of limited area, in Ireland, Wales, Cumberland, and the 

 extreme south-west of Scotland it is even greater, but these 

 cases must be regarded as exceptional ones due to local causes ; 

 on the other hand the annual rainfall in the eastern and midland 

 counties ranges from 20 to 22 inches. In] Jeddo the registered 

 annual rainfall is 70 inches, with a gradual decrease northwards 

 towards Yesso, where, in the absence of meteorological stations, 

 it is estimated to be not much greater than in the midland coun- 

 ties of England ; southwards from Jeddo the rainfall in each 

 year seldom sinks below 50 inches. As the Gulf Stream exercises 

 a great influence on the hygrometric condition of our atmosphere, 

 so there is an analogous agency at work in Japan, which has a 

 still greater influence on its climate ; this is the north equatorial 

 current of the great Pacific Ocean. This current flows west- 

 ward parallel with the northern tropic till it reaches the island 

 of Formosa, near the coast of China ; it thence turns northward, 

 when it becomes known as the Japan current, washes the 

 southern shores of Kiusiu and Sikok, the southernmost of the 

 Japanese islands, where its influence on the temperature and 

 moisture of the climate is so great that such tropical Orchideas 

 as Dendrobium, Aerides, Angrrecum, and Calanthe are indigenous. 

 Continuing its course along the eastern shore of Nippon, the 

 atmospheric humidity of Central Japan, through its means, Dr. 



