345 



SUMMAEY. 



I. The 859 species may be thus classified : — 



Native ......... 768 



Introduced, and more or less completely naturalised, marked with an 

 asterisk (*) in the Flora ....... 91 



Total . . . .859 



There are also about 120 other species mentioned which have been met with 

 as casuals, garden escapes, or accidental introductions ; but these are omitted 

 in all the following summaries and comparisons. 



II. No less than 58 species are probably extinct. This indicates that 

 many localities have been destroyed. The same thing is illustrated by the 

 very large proportion of ' rare ' species ; though this may be lessened by 

 further investigation. The plants of Middlesex, when arranged in accord- 

 ance with their relative frequency (see p. 2), give this result : — 



Very common . 

 Common 

 Rather common 

 Rather rare 

 Rare 

 Very rare 



Extinct . 



The probably extinct species are these 



Still exists (see Addenda). 



