:6.S The Irish Naturalist, December, 190S. 



The Burnt Q-round on Howth Head. 



Perhaps it \\\c\\ be desirable to add a lew remarks to iny previous com- 

 munication on this subject. And. lirst, let me say, that had the fire been 

 one of ordinary intensity, I should not have thought it worth referring 

 to. But it occurred after a period of continued drought, and the thin 

 layer of peat below the vegetation smouldered for a long time after the 

 brunt of the fire had passed. It is quite true that towards the edge of 

 the burnt area some of the vegetation escaped, but in making out my 

 list of species I avoided these places, selecting the more central region 

 where the fire had done its work most completely. In fact, as I men- 

 tioned, I came across only one individual of Bracken and one of Whin 

 which were sprouting from the old stems. 



Although seedling "Whins were one of the most dominant species still, 

 the total number of individuals was few, as there are still large patches 

 of ^soil devoid of vegetation of an}' kind. These seedlings were most 

 numerous on one side of the burnt ground, and near this spot there is a 

 clump of Whins growing on the area just outside the burnt zone. On 

 the date of my last visit (5th Sept , 1908), the wind was blowing direct!}- 

 from the clump of Whins over the spot where the seedlings were. But 

 higher up, and nearer the centre of the burnt area, some seedlings were 

 observed, and numerous charred stems of the old Whin bushes. The 

 distance in this case is too great, I fancy, for the seeds to have been 

 ejected by the explosion of the fruit of the parent plant, or to have been 

 carried by wind, and there is a strong probability, therefore, that they 

 survived the fire. But 1 suggested the possibility of this in my previous 

 account of the species observed. I may add that Ulex Gallii does occur 

 on the burnt ground, as it is now in flower. Other seedlings higher up 

 may prove to be U. europcviis. 



With regard to most of the other species observed, I do not see any 

 necessity to assume that they survived the fire. The wind, at an altitude 

 of 500 feet, could easily carry them the required distance. Aim prcccox 

 increases in number of individuals towards the edge of the burnt area 

 just outside which the parent plants may still be found growing. But it 

 we assume that this and other species (except Whin) survived the fire, 

 the seeds must have been already present on the surface of the soil. They 

 must have been carried to these places by wind or other agenc} , and, if 

 wind could transport them before the fire, there is nothing unreasonable 

 in assuming that the same agent could carry them after it. As I stated 

 in the July number of the Iristi Nafura/isl, my list of species was made 

 two years after the fire, not three. 



J. ADA:\rs. 



Roval College of Science. Dublin. 



