C. L. Walton 
253 
Hafod) while Machynlleth 41 feet, and nearer the sea, has a rainfall 
equalling Hafod. In the Plynlymon region the average fall may exceed 
100 inches. It will be seen however from Table I that although they 
differ in volume there is yet a great similarity in the form of the graphs. 
It will further be noted that the years 1910, ’12 and ’13, were wet, 
that is, the period leading up to and including the attack of rot. 
Aberystwyth. - 
Goyerdd&rt ---— r- 
h/czjod . 
Machynlleth.. 
Fig. 2. Annual Rainfall—Aberystwyth Area, 1905-1915. 
A very important point however, is the distribution of rainfall 
throughout the year and Table I gives the rainfall and number of days 
when rain fell at three of the local centres for 1910, ’ll and ’12, this 
shows that the number of raining days remains remarkably constant 
although the total amount of precipitation may vary considerably. 
Parasitology x 17 
