PLANT DISTEIBITTION. 181 



Henbane and Viper's Bugloss have failed to acclimatize them- 

 selves at the latter. The same may be said of Trifolium 

 subterraneum and the Borage, which grow in the neighbourhood 

 of Penzance ; of Trifolium arvense, which grows in different 

 parts of the county ; and of the several others which failed 

 to settle with us. 



Contemplating our list of wanderers again, something of 

 importance will be suggested. It will be seen that, with but one 

 exception {Impatiens parviflora), the wanderers which have become 

 naturalised are perennials, while those which failed to secure a 

 permanent hold on the soil were all annuals and biennials. 



Now, on this particular point what does Nature teach us ? 

 If a small plot of ground is trenched over and allowed to remain, 

 the first plants to appear will be very largely annuals- Later 

 biennials and perennials will gain the ascendency, and the 

 annuals will be reduced to a very low minimum. But it must be 

 distinctly emphasised that where Nature enjoys her pristine 

 wildness this scratching of the surface of the soil with harrow 

 and plough is quite unknown, hence the speedy growth of 

 annuals after these processes is not to be accepted as indicative 

 of the way in which plant distribution was carried on in 

 ancient times. The only natural influences analogous to 

 cultivation are the "weathering" of the face of the country by 

 atmospheric changes, the clearing of the land by extensive fires, 

 and the action of rivers &c., in throwing up banks of mud 

 and sand. 



What then shall we say ? Does the trend of Nature, the 

 "struggle for existence" in the vegetable world, favour 

 perennials ; and have the wanderings of annuals, depending as 

 they do in Nature's wilds oq slowly operating or accidental 

 causes to prepare the soil, been less direct, less regular ? It is 

 a notorious fact that wherever Nature has her own way the 

 endemic flora is largely perennial ; and on the writer carefullv 

 reviewing the census of stations of the British flora as given in 

 the "London Catalogue," he was met by the interesting fact, 

 that perennials have generally the widest distribution, and that 

 whenever annuals have high records they are almost always 



