234 Lees : The Volte face of Flora— A Rejoinder. 



storm or other cataclysm of nature so as to lay bare for a bit 

 under new conditions some ground for the life lying in the soil. 

 But . . , trees once covered these hills, we know ! And 

 in our day it sufficeth to say that the springy carpet of wiry 

 perennial growth that lies over so much of its higher plateaux, 

 protects the ground from assault, ay ! prevents — puts off, that 

 change in the flora which under altered conditions must ensue. 

 To me no verity is more certain than this. 



I am, of course, not unaware how very long and strangely 

 some plants will prevail ; the flora of a large area, like Scotland, 

 or Ireland, has not in two hundred and fifty years lost entirely 

 above a dozen species, and those mainly of sea-coasts ; yet in 

 other areas a twentieth the size, notably Lincolnshire and 

 Lancashire, the change and substitution concurring with altera- 

 tions in the character of big districts, is well marked : it extends 

 to as many as twenty former incoles now quite extinct ; and this 

 is well known to those field observers whose practical acquaint- 

 ance extends over even a quarter of a century. I am a little 

 concerned at the quarter from which opponent criticism of my 

 truism of ' Change ' is coming. I fancy I tipped some of the 

 arrows myself in epistolary communications written currente 

 calamo, and giving, along with asked-for information, spur-of- 

 the-moment views of this Halifax ' species ' or that, too hastily 

 formed. My conclusions have not remained rigid and fixed 

 since 1895. The many recent facts I could adduce from my 

 note-books I had fancied only bore out the observation of most 

 of our older-hand botanists. And the researches of Mr. Clement 

 Reid into the fossil seeds of the late-glacial deposits bear out 

 my thesis, and prove incoiftestibly that over wide tracts many 

 plants 'Were,' which in the same locations, now, 'Are Not.' 



To draw to an end, on the whole Mr. Moss's views and 

 mine are fairly in agreement. I can endorse his able summary 

 on p. 17 1 -2, when he admits that physiographic factors are 

 'operative.' If at all, who can limit the effect of successive 

 applications of the helm — the physical cause, on the course 

 vegetation takes afterwards ? In affairs floral is there no tack- 

 ing, no water-leak, no drifting shoreward, never any foundering? 

 Leaving metaphor, I admit that introduction of ' fresh types ' is 

 exceptional ; but much more exceptional in a rugged, moory, 

 elevated area like Halifax than in one such as that about 

 Reading, or Kidderminster ; where new items in the flora have 

 replaced old ones by scores — Diplotaxis instead of Hieracium, by 

 millions on the embankments. To revert to the particular, again, 



Naturalist. 



