INTRODUCTORY ESSAY. 35 



and perpetuated by cuttings. Similar examples are afforded 



our domestic iruit-trees, amon 



e, many different sorts can be recognized at once. 

 In conclusion, the majority of our readers will smile when 

 ! add that the general impression of persons of intelligence, 

 at they know our common English trees at first sight, is to 



great degree illusory 



come 



abnormal 



not characteristic ; but let any one keep a watch upon himself 

 in the fields, parks, or forests of countries not his own, yet 

 tenanted by trees specifically the same as those of his own, 

 and we venture to assert that he will find his preconceived 



ground in very many cases. We 



mean 



willow: but we do assert that he will 



recognize by habit the same oak at the Cape of Good Hop 



same yew in 



may add that no Himalayan traveller within our 



return to England, ever recogm 



Kew 



mountains, and that, on the contrary, we have frequently had 



Cedar 



much to be wished 



commence 



hould 



deavour, by selecting good suites of specimens, produced under 

 all variations of circumstances, to determine how few, not how 

 many species are comprised in the flora of his district. The 

 permanent differences will, he may depend upon it, soon force 

 themselves upon his attention, whilst those which are non- 

 essential will consecutively be eliminated. There is no better 

 way of proving the validity of characters than by attempting 

 to invalidate them. The unavoidable tendency of the human 

 mind, when occupied with the pursuit of minute differenc * 



tr* B m m «* 4-1 i , -i-u r,i ;,Kf^ an/1 in lvliiiniiisli tlu u uith i 



