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Transactions of the Royal Society of South Africa. 
terised by their smooth, fulvous, almost velvety surface, which extends over 
the edge on to the lower surface. 
The substance of the pileus is hard and woody and of a raw sienna 
colour ; a section shows the outer rind to be inclined towards Vandyke 
brown. The whole sporophore is exceedingly hard and woody. 
The lower surface of the sporophore is a dull reddish-brown and smooth 
and velvety to the touch. The pores are minute, on the average 112-132 fx 
across, hardly discernible to the naked eye, 3-5 to the mm. ; dissepiments 
rather thick, on the average 78-125 /x, and poremouths entire and 
circular. 
The tubes are arranged in strata, not always very distinct, 2-6 mm. long, 
and are a light brown (raw sienna). They extend practically to the surface, 
there being only a thin, hard, woody context tissue '3 -1 cm. thick and zoned. 
The tubes of the older strata later become plugged by mycelial hyphae, and 
this 2)lugging appears to start irregularly in any particular layer. As has 
also been pointed out by other writers, a large number of spores are frequently 
imprisoned in these plugged-up tubes. 
The spores (Fig. 14) are abundant, yellowish-brown, smooth, globose, or 
slightly oval, 4*35-5 /x diameter. Setae are absent. 
The fructifications do not form after the trees are dead, nor does the 
diseased wood when used for poles, etc., continue to rot. This was also 
reported by von Schrenk * for the locust tree, and would suggest, as pointed 
out by him, that conditions in the living tree must be essentially different 
from those existing after the tree is dead. 
The description of the fructification is from sj^ecimens taken from 
Sneezewood, and the size that most frequently met with on the above tree. 
The largest specimen (frontispiece) seen by the author was from Elaeodendron 
croceum (saft'ron wood) and measured 73 x 36 x 28 cms. Its weight was 
24i lb. It was collected at Knysna by Mr. C. E. Legat, Chief Conservator 
of Forests for the Union. 
Control of the Heart Rot caused by Fomes rimosus. 
We have seen that Fonies rimosus is a wound j)arasite, and the two 
methods of control which suggest themselves are : 
(1) The prevention of wounds. 
(2) The removal of the primary sources of infection. 
Whereas on large areas it would be practically impossible, from an 
economic point of view, to treat trees individually, yet nevertheless much can 
be done in a general way to lessen the chances of natural wound infection. 
The most practical method for combating heart rot is undoubtedly the 
* Schrenk, Herman von, op, cit., p. 29, 
