210 Transactions British Mycological Society. 



dry slightly, and a third species would be made of E on potato, 

 The one name Corticium vagum B. & C. = {Rhizoctonia Solani 

 Kiihn) is, therefore, retained for the isolations compared in this 

 paper at the same time realising that the species contains several 

 biological species or strains. 



BIBLIOGRAPHY, 

 (i) DuGGAR, B. M. Rhizoctonia Croconim (Pers.) DC. and R. Solani Kiihn 



(Corticium vagum B. & C.) with notes on other species. Ann. Miss. Bot. 



Gdns. II. pp. 403-458. (1915-) 

 (2) Matz, J. The Rhizoctonias of Porto Rico. Journ Dept. of Agric, Porto 



Rico. V, No. I. Jan. 1921. 



SOME OBSERVATIONS ON FISTULINA 



HEPATICA AND HOLLOW, 



STAG-HEADED OAKS. 



By K. W. Braid, B.A., B.Sc. 



Few trees appeal more strongly to the popular imagination 

 than oaks, hence their defoliation by Tortrix or the bepowdering 

 of their leaves by Oidium offends the national eye and heart. 

 Many, who have no hint of the causes, bemoan the appearance 

 of the stag-headed giants of our parks and forests. 



In 192 1 and 1923 there was a surprising abundance of 

 Fistidina hepatica Fr. on the oaks in Richmond Park. On 

 September 8th, 1923, a stipitate specimen was found growing 

 in the dark cavity of a hollow oak, and a few yards away on a 

 branch of another tree a normal specimen was found. Three 

 weeks later a count of twenty trees showed that twelve possessed 

 ripe fungus fructifications. That is, about 60 per cent, actually 

 bore the fungus in fruit, or, counting the two trees which had 

 possessed sporophores on the 8th and which had been numbered 

 amongst the selected twenty, 70 per cent, of the trees bore, or 

 had borne, fructifications during the year. A more extended 

 count confirmed these figures. The following day another count 

 was made in a different part of the Park. As before, old trees 

 were chosen which were at least two feet in diameter at three 

 feet above ground level, and Fistulina hepatica was found 

 on 75 per cent, of the trees. Sometimes the fructifications were 

 on the buttresses of the roots, sometimes on the bark of the 

 trunk, but usually were well up on the larger limbs. Later, in 

 the case of an old felled stump, a Fistulina was seen growing 

 vertically upon the cut upper surface near the centre of the 

 stump. The following week in a different part of the park 



