548 



families. The second table contains a list of the plants that more 

 particularly distinguish the district. In drawing up this table, those 

 species have been selected that are admitted into Mr. Watson's ' New- 

 Botanist's Guide,' which contains only the plants found not to be 

 common to eight out of twelve local Floras of Great Britain. I have 

 followed Mr. Watson in this respect, not because I think his list the 

 best that could be constructed, but because his book is very generally 

 known to botanists in this country. Since the publication of Mr. 

 Watson's book, other Floras have been published, and materials fiir- 

 nished for a more correct list of common plants than he has given ; 

 and I would suggest that it might be worth the while of some of our 

 botanical societies to construct a list, which, by excluding common 

 plants, would enable the botanist to publish only the peculiar and 

 most interesting forms. But these two tables, even with Mr. Watson^s 

 Guide and a British Flora, would give only an incomplete view of the 

 Flora of a particular district, since many of the common as well as of 

 the rarer plants might be absent from it. In order to meet this defect, 

 I have constructed a third table, including the plants which were com- 

 mon to the twelve counties examined by Mr. Watson, but which I did 

 not find near Askern. In the present case I believe this table to be 

 somewhat imperfect, but I have mentioned it in order to show the 

 manner in which my plan may be carried out. With these three ta- 

 bles, a list of British plants, and Mr. Watson's Guide, we have the 

 elements of a complete Flora of a district. 



There is, however, one point in which such a Flora would be defec- 

 tive, and that is the comparative rarity or frequency of the excluded 

 common plants. This is, however, always a difficult point to estimate, 

 and little has hitherto been done towards enabling us to compute, with 

 any proximity to the truth, the number of individual plants growing 

 in a district. In my fourth table, by way of meeting in some measure 

 this inconvenience, I have added the names of a few plants which are 

 rare in the Askern district, but which are excluded as common from 

 Mr. Watson s list. Edwin Lankester. 



19, Golden Square, 

 January, 1843. 



[We are greatly obliged to Dr. Lantester for his valuable suggestions ; tbe adop- 

 tion of his plan would, however, involve the necessity of printing at least four lists in- 

 stead of one for every district illustrated. The subject of publishing local lists of plants 

 is one which has often had our serious consideration. For various reasons we have 

 hitherto preferred printing them exactly as received from the contributors, to whom 

 our thanks are due for the pains they have taken to render their lists correct and com- 



