OATAIOGUES. 565 



introduced or truly indigenous in the area under observation, 

 and the remarkable confusion often made between eye -sight 

 and hear-say evidence, — a series of four marks was adopted for 

 the sake of uniformity among the lists, or such an approxi- 

 mation towards uniformity as it was found possible to obtain. 

 The four marks were these : — 



- Native in the area, seen there by the Marker himself. 



t Possibly introduced there. Ditto. 



* Probably (or Certainly) introduced. Ditto. 



o Eeported'on or by some other authority. 

 This seems clear and simple enough. It has not been found 

 so in practice. There were Catalogues in which Semperdvum 

 teetotum and Elodea canadensis, were at first marked as true 

 natives. The ordinary corn-field weeds, the Colonists of the 

 Cybele Britannica, are marked as natives usually, but occa- 

 sionally as introductions, in neighbouring counties where they 

 really occur under almost precisely similar conditions. Planted 

 trees are marked variously, either as natives or as possibly or 

 probably introduced. Even the wide difference of meaning 

 between " - " and " o " has not always been faithfully adhered 

 to. Still, be it observed, such incongruities may be found in 

 the printed Local Floras, as" well as in the Catalogues cited in 

 this present work. And on the whole, the Catalogues here 

 under explanation, and cited on preceding pages, after having 

 been critically considered, are probably quite equal in trust- 

 worthiness to the printed Floras. Indeed, if a like number of 

 each should be fairly compared together, it would assuredly be 

 found that the printed Floras include more errors ; that they 

 have given currency and record to far more errors in the names 

 and locaUties of plants, than the -Catalogues cited in this 

 present work will do. 



In their several dates, they may be described as ranging from 

 1832 to 1880 inclusive. It is important to bear in mind this 

 lengthened range of date, when looking to their evidence as 

 shewing the occurrence of particular plants within their 



