224 
Jean Dufrenoy . 
Fig. II. Stem tubercle. (1) External view. *St., stem; sh. t shoots; r., roots. 
(2) Section along plane in 1, showing area of starch grains. (3) A portion 
of 2 x 500. /., wood fibres, v., vessels, m., medullary raj' cells crowded with 
starch grains. (4) Normal medullary ray from stem. 
with big starch grains (Pig. II, 1, 2, 3, 4). Here and there tubercles 
appear laterally on the roots or on the shoots, where they may 
cause the epidermis to burst, and so result in a wound (Pig. Ill, 1). 
In all these tubercles the fungus is rather conspicuous, but it can be 
traced by careful investigation 1 in all the tissues of the roots, shoots, 
leaves and fruits. 
The inflorescences of Arbutus contain numerous flowers; but 
’ Sections of fresh tissues should be examined in Lactophenol or in a water 
solution of iodine and iodide of potassium. Sections may also be stained in 
eosin solution and then washed out in a solution of hj'drochloric acid until the 
fungus appears clearlj' differentiated. 
